diff --git a/app/assets/javascripts/copy_to_clipboard.js b/app/assets/javascripts/copy_to_clipboard.js
index 6dbec50b890..ab9a8e43dd1 100644
--- a/app/assets/javascripts/copy_to_clipboard.js
+++ b/app/assets/javascripts/copy_to_clipboard.js
@@ -38,9 +38,35 @@ showTooltip = function(target, title) {
 };
 
 $(function() {
-  var clipboard;
-
-  clipboard = new Clipboard('[data-clipboard-target], [data-clipboard-text]');
+  const clipboard = new Clipboard('[data-clipboard-target], [data-clipboard-text]');
   clipboard.on('success', genericSuccess);
-  return clipboard.on('error', genericError);
+  clipboard.on('error', genericError);
+
+  // This a workaround around ClipboardJS limitations to allow the context-specific copy/pasting of plain text or GFM.
+  // The Ruby `clipboard_button` helper sneaks a JSON hash with `text` and `gfm` keys into the `data-clipboard-text`
+  // attribute that ClipboardJS reads from.
+  // When ClipboardJS creates a new `textarea` (directly inside `body`, with a `readonly` attribute`), sets its value
+  // to the value of this data attribute, focusses on it, and finally programmatically issues the 'Copy' command,
+  // this code intercepts the copy command/event at the last minute to deconstruct this JSON hash and set the
+  // `text/plain` and `text/x-gfm` copy data types to the intended values.
+  $(document).on('copy', 'body > textarea[readonly]', function(e) {
+    const clipboardData = e.originalEvent.clipboardData;
+    if (!clipboardData) return;
+
+    const text = e.target.value;
+
+    let json;
+    try {
+      json = JSON.parse(text);
+    } catch (ex) {
+      return;
+    }
+
+    if (!json.text || !json.gfm) return;
+
+    e.preventDefault();
+
+    clipboardData.setData('text/plain', json.text);
+    clipboardData.setData('text/x-gfm', json.gfm);
+  });
 });
diff --git a/app/helpers/blob_helper.rb b/app/helpers/blob_helper.rb
index 91d6d1852cf..14f9b237a51 100644
--- a/app/helpers/blob_helper.rb
+++ b/app/helpers/blob_helper.rb
@@ -210,13 +210,13 @@ module BlobHelper
   end
 
   def copy_file_path_button(file_path)
-    clipboard_button(clipboard_text: file_path, class: 'btn-clipboard btn-transparent prepend-left-5', title: 'Copy file path to clipboard')
+    clipboard_button(text: file_path, gfm: "`#{file_path}`", class: 'btn-clipboard btn-transparent prepend-left-5', title: 'Copy file path to clipboard')
   end
 
   def copy_blob_content_button(blob)
     return if markup?(blob.name)
 
-    clipboard_button(clipboard_target: ".blob-content[data-blob-id='#{blob.id}']", class: "btn btn-sm", title: "Copy content to clipboard")
+    clipboard_button(target: ".blob-content[data-blob-id='#{blob.id}']", class: "btn btn-sm", title: "Copy content to clipboard")
   end
 
   def open_raw_file_button(path)
diff --git a/app/helpers/button_helper.rb b/app/helpers/button_helper.rb
index 0b30471f2ae..c85e96cf78d 100644
--- a/app/helpers/button_helper.rb
+++ b/app/helpers/button_helper.rb
@@ -1,23 +1,42 @@
 module ButtonHelper
   # Output a "Copy to Clipboard" button
   #
-  # data - Data attributes passed to `content_tag`
+  # data  - Data attributes passed to `content_tag` (default: {}):
+  #         :text   - Text to copy (optional)
+  #         :gfm    - GitLab Flavored Markdown to copy, if different from `text` (optional)
+  #         :target - Selector for target element to copy from (optional)
   #
   # Examples:
   #
   #   # Define the clipboard's text
-  #   clipboard_button(clipboard_text: "Foo")
+  #   clipboard_button(text: "Foo")
   #   # => "<button class='...' data-clipboard-text='Foo'>...</button>"
   #
   #   # Define the target element
-  #   clipboard_button(clipboard_target: "div#foo")
+  #   clipboard_button(target: "div#foo")
   #   # => "<button class='...' data-clipboard-target='div#foo'>...</button>"
   #
   # See http://clipboardjs.com/#usage
   def clipboard_button(data = {})
     css_class = data[:class] || 'btn-clipboard btn-transparent'
     title = data[:title] || 'Copy to clipboard'
+
+    # This supports code in app/assets/javascripts/copy_to_clipboard.js that
+    # works around ClipboardJS limitations to allow the context-specific copy/pasting of plain text or GFM.
+    if text = data.delete(:text)
+      data[:clipboard_text] =
+        if gfm = data.delete(:gfm)
+          { text: text, gfm: gfm }
+        else
+          text
+        end
+    end
+
+    target = data.delete(:target)
+    data[:clipboard_target] = target if target
+
     data = { toggle: 'tooltip', placement: 'bottom', container: 'body' }.merge(data)
+
     content_tag :button,
       icon('clipboard', 'aria-hidden': 'true'),
       class: "btn #{css_class}",
diff --git a/app/views/profiles/personal_access_tokens/index.html.haml b/app/views/profiles/personal_access_tokens/index.html.haml
index 0645ecad496..c852107e69a 100644
--- a/app/views/profiles/personal_access_tokens/index.html.haml
+++ b/app/views/profiles/personal_access_tokens/index.html.haml
@@ -19,7 +19,7 @@
           Your New Personal Access Token
         .form-group
           = text_field_tag 'created-personal-access-token', flash[:personal_access_token], readonly: true, class: "form-control", 'aria-describedby' => "created-personal-access-token-help-block"
-          = clipboard_button(clipboard_text: flash[:personal_access_token], title: "Copy personal access token to clipboard", placement: "left")
+          = clipboard_button(text: flash[:personal_access_token], title: "Copy personal access token to clipboard", placement: "left")
           %span#created-personal-access-token-help-block.help-block.text-danger Make sure you save it - you won't be able to access it again.
 
       %hr
diff --git a/app/views/projects/_last_push.html.haml b/app/views/projects/_last_push.html.haml
index a08436715d2..ee7d4e36d4b 100644
--- a/app/views/projects/_last_push.html.haml
+++ b/app/views/projects/_last_push.html.haml
@@ -10,7 +10,7 @@
             - if @project && event.project != @project
               %span at
               %strong= link_to_project event.project
-            = clipboard_button(clipboard_text: event.ref_name, class: 'btn-clipboard btn-transparent', title: 'Copy branch to clipboard')
+            = clipboard_button(text: event.ref_name, class: 'btn-clipboard btn-transparent', title: 'Copy branch to clipboard')
             #{time_ago_with_tooltip(event.created_at)}
 
           .pull-right
diff --git a/app/views/projects/commit/_commit_box.html.haml b/app/views/projects/commit/_commit_box.html.haml
index a0a292d0508..fa951792569 100644
--- a/app/views/projects/commit/_commit_box.html.haml
+++ b/app/views/projects/commit/_commit_box.html.haml
@@ -1,7 +1,7 @@
 .page-content-header
   .header-main-content
     %strong Commit #{@commit.short_id}
-    = clipboard_button(clipboard_text: @commit.id, title: "Copy commit SHA to clipboard")
+    = clipboard_button(text: @commit.id, title: "Copy commit SHA to clipboard")
     %span.hidden-xs authored
     #{time_ago_with_tooltip(@commit.authored_date)}
     %span by
diff --git a/app/views/projects/commits/_commit.html.haml b/app/views/projects/commits/_commit.html.haml
index 4b1ff75541a..8f32d2b72e5 100644
--- a/app/views/projects/commits/_commit.html.haml
+++ b/app/views/projects/commits/_commit.html.haml
@@ -37,6 +37,6 @@
       .commit-actions.flex-row.hidden-xs
         - if commit.status(ref)
           = render_commit_status(commit, ref: ref)
-        = clipboard_button(clipboard_text: commit.id, title: "Copy commit SHA to clipboard")
+        = clipboard_button(text: commit.id, title: "Copy commit SHA to clipboard")
         = link_to commit.short_id, namespace_project_commit_path(project.namespace, project, commit), class: "commit-short-id btn btn-transparent"
         = link_to_browse_code(project, commit)
diff --git a/app/views/projects/issues/_issue_by_email.html.haml b/app/views/projects/issues/_issue_by_email.html.haml
index d2038a2be68..da65157a10b 100644
--- a/app/views/projects/issues/_issue_by_email.html.haml
+++ b/app/views/projects/issues/_issue_by_email.html.haml
@@ -16,7 +16,7 @@
         .email-modal-input-group.input-group
           = text_field_tag :issue_email, email, class: "monospace js-select-on-focus form-control", readonly: true
           .input-group-btn
-            = clipboard_button(clipboard_target: '#issue_email')
+            = clipboard_button(target: '#issue_email')
         %p
           The subject will be used as the title of the new issue, and the message will be the description.
 
diff --git a/app/views/projects/merge_requests/show/_how_to_merge.html.haml b/app/views/projects/merge_requests/show/_how_to_merge.html.haml
index cde0ce08e14..f3372c7657f 100644
--- a/app/views/projects/merge_requests/show/_how_to_merge.html.haml
+++ b/app/views/projects/merge_requests/show/_how_to_merge.html.haml
@@ -8,7 +8,7 @@
         %p
           %strong Step 1.
           Fetch and check out the branch for this merge request
-        = clipboard_button(clipboard_target: "pre#merge-info-1", title: "Copy commands to clipboard")
+        = clipboard_button(target: "pre#merge-info-1", title: "Copy commands to clipboard")
         %pre.dark#merge-info-1
           - if @merge_request.for_fork?
             :preserve
@@ -25,7 +25,7 @@
         %p
           %strong Step 3.
           Merge the branch and fix any conflicts that come up
-        = clipboard_button(clipboard_target: "pre#merge-info-3", title: "Copy commands to clipboard")
+        = clipboard_button(target: "pre#merge-info-3", title: "Copy commands to clipboard")
         %pre.dark#merge-info-3
           - if @merge_request.for_fork?
             :preserve
@@ -38,7 +38,7 @@
         %p
           %strong Step 4.
           Push the result of the merge to GitLab
-        = clipboard_button(clipboard_target: "pre#merge-info-4", title: "Copy commands to clipboard")
+        = clipboard_button(target: "pre#merge-info-4", title: "Copy commands to clipboard")
         %pre.dark#merge-info-4
           :preserve
             git push origin #{h @merge_request.target_branch}
diff --git a/app/views/projects/pipelines/_info.html.haml b/app/views/projects/pipelines/_info.html.haml
index 4be9a1371ec..fc1d0989787 100644
--- a/app/views/projects/pipelines/_info.html.haml
+++ b/app/views/projects/pipelines/_info.html.haml
@@ -46,4 +46,4 @@
         \...
     %span.js-details-content.hide
       = link_to @pipeline.sha, namespace_project_commit_path(@project.namespace, @project, @pipeline.sha), class: "monospace commit-hash-full"
-    = clipboard_button(clipboard_text: @pipeline.sha, title: "Copy commit SHA to clipboard")
+    = clipboard_button(text: @pipeline.sha, title: "Copy commit SHA to clipboard")
diff --git a/app/views/projects/registry/repositories/_tag.html.haml b/app/views/projects/registry/repositories/_tag.html.haml
index ee1ec0e8f9a..854b7d0ebf7 100644
--- a/app/views/projects/registry/repositories/_tag.html.haml
+++ b/app/views/projects/registry/repositories/_tag.html.haml
@@ -1,7 +1,7 @@
 %tr.tag
   %td
     = escape_once(tag.name)
-    = clipboard_button(clipboard_text: "docker pull #{tag.path}")
+    = clipboard_button(text: "docker pull #{tag.path}")
   %td
     - if tag.revision
       %span.has-tooltip{ title: "#{tag.revision}" }
diff --git a/app/views/projects/services/mattermost_slash_commands/_detailed_help.html.haml b/app/views/projects/services/mattermost_slash_commands/_detailed_help.html.haml
index 2fb88297fb3..ef3599460f1 100644
--- a/app/views/projects/services/mattermost_slash_commands/_detailed_help.html.haml
+++ b/app/views/projects/services/mattermost_slash_commands/_detailed_help.html.haml
@@ -22,14 +22,14 @@
     .col-sm-10.col-xs-12.input-group
       = text_field_tag :display_name, "GitLab / #{@project.name_with_namespace}", class: 'form-control input-sm', readonly: 'readonly'
       .input-group-btn
-        = clipboard_button(clipboard_target: '#display_name')
+        = clipboard_button(target: '#display_name')
 
   .form-group
     = label_tag :description, 'Description', class: 'col-sm-2 col-xs-12 control-label'
     .col-sm-10.col-xs-12.input-group
       = text_field_tag :description, run_actions_text, class: 'form-control input-sm', readonly: 'readonly'
       .input-group-btn
-        = clipboard_button(clipboard_target: '#description')
+        = clipboard_button(target: '#description')
 
   .form-group
     = label_tag nil, 'Command trigger word', class: 'col-sm-2 col-xs-12 control-label'
@@ -46,7 +46,7 @@
     .col-sm-10.col-xs-12.input-group
       = text_field_tag :request_url, service_trigger_url(subject), class: 'form-control input-sm', readonly: 'readonly'
       .input-group-btn
-        = clipboard_button(clipboard_target: '#request_url')
+        = clipboard_button(target: '#request_url')
 
   .form-group
     = label_tag nil, 'Request method', class: 'col-sm-2 col-xs-12 control-label'
@@ -57,14 +57,14 @@
     .col-sm-10.col-xs-12.input-group
       = text_field_tag :response_username, 'GitLab', class: 'form-control input-sm', readonly: 'readonly'
       .input-group-btn
-        = clipboard_button(clipboard_target: '#response_username')
+        = clipboard_button(target: '#response_username')
 
   .form-group
     = label_tag :response_icon, 'Response icon', class: 'col-sm-2 col-xs-12 control-label'
     .col-sm-10.col-xs-12.input-group
       = text_field_tag :response_icon, asset_url('gitlab_logo.png'), class: 'form-control input-sm', readonly: 'readonly'
       .input-group-btn
-        = clipboard_button(clipboard_target: '#response_icon')
+        = clipboard_button(target: '#response_icon')
 
   .form-group
     = label_tag nil, 'Autocomplete', class: 'col-sm-2 col-xs-12 control-label'
@@ -75,14 +75,14 @@
     .col-sm-10.col-xs-12.input-group
       = text_field_tag :autocomplete_hint, '[help]', class: 'form-control input-sm', readonly: 'readonly'
       .input-group-btn
-        = clipboard_button(clipboard_target: '#autocomplete_hint')
+        = clipboard_button(target: '#autocomplete_hint')
 
   .form-group
     = label_tag :autocomplete_description, 'Autocomplete description', class: 'col-sm-2 col-xs-12 control-label'
     .col-sm-10.col-xs-12.input-group
       = text_field_tag :autocomplete_description, run_actions_text, class: 'form-control input-sm', readonly: 'readonly'
       .input-group-btn
-        = clipboard_button(clipboard_target: '#autocomplete_description')
+        = clipboard_button(target: '#autocomplete_description')
 
 %hr
 
diff --git a/app/views/projects/services/slack_slash_commands/_help.html.haml b/app/views/projects/services/slack_slash_commands/_help.html.haml
index 078b7be6865..73b99453a4b 100644
--- a/app/views/projects/services/slack_slash_commands/_help.html.haml
+++ b/app/views/projects/services/slack_slash_commands/_help.html.haml
@@ -40,7 +40,7 @@
         .col-sm-10.col-xs-12.input-group
           = text_field_tag :url, service_trigger_url(subject), class: 'form-control input-sm', readonly: 'readonly'
           .input-group-btn
-            = clipboard_button(clipboard_target: '#url')
+            = clipboard_button(target: '#url')
 
       .form-group
         = label_tag nil, 'Method', class: 'col-sm-2 col-xs-12 control-label'
@@ -51,7 +51,7 @@
         .col-sm-10.col-xs-12.input-group
           = text_field_tag :customize_name, 'GitLab', class: 'form-control input-sm', readonly: 'readonly'
           .input-group-btn
-            = clipboard_button(clipboard_target: '#customize_name')
+            = clipboard_button(target: '#customize_name')
 
       .form-group
         = label_tag nil, 'Customize icon', class: 'col-sm-2 col-xs-12 control-label'
@@ -68,21 +68,21 @@
         .col-sm-10.col-xs-12.input-group
           = text_field_tag :autocomplete_description, run_actions_text, class: 'form-control input-sm', readonly: 'readonly'
           .input-group-btn
-            = clipboard_button(clipboard_target: '#autocomplete_description')
+            = clipboard_button(target: '#autocomplete_description')
 
       .form-group
         = label_tag :autocomplete_usage_hint, 'Autocomplete usage hint', class: 'col-sm-2 col-xs-12 control-label'
         .col-sm-10.col-xs-12.input-group
           = text_field_tag :autocomplete_usage_hint, '[help]', class: 'form-control input-sm', readonly: 'readonly'
           .input-group-btn
-            = clipboard_button(clipboard_target: '#autocomplete_usage_hint')
+            = clipboard_button(target: '#autocomplete_usage_hint')
 
       .form-group
         = label_tag :descriptive_label, 'Descriptive label', class: 'col-sm-2 col-xs-12 control-label'
         .col-sm-10.col-xs-12.input-group
           = text_field_tag :descriptive_label, 'Perform common operations on GitLab project', class: 'form-control input-sm', readonly: 'readonly'
           .input-group-btn
-            = clipboard_button(clipboard_target: '#descriptive_label')
+            = clipboard_button(target: '#descriptive_label')
 
     %hr
 
diff --git a/app/views/projects/tree/_tree_content.html.haml b/app/views/projects/tree/_tree_content.html.haml
index 6855c463c6d..2497a2d91b1 100644
--- a/app/views/projects/tree/_tree_content.html.haml
+++ b/app/views/projects/tree/_tree_content.html.haml
@@ -10,7 +10,7 @@
               %i.fa.fa-angle-right
               %small.light
                 = link_to @commit.short_id, namespace_project_commit_path(@project.namespace, @project, @commit), class: "monospace"
-                = clipboard_button(clipboard_text: @commit.id, title: "Copy commit SHA to clipboard")
+                = clipboard_button(text: @commit.id, title: "Copy commit SHA to clipboard")
                 = time_ago_with_tooltip(@commit.committed_date)
                 \-
                 = @commit.full_title
diff --git a/app/views/projects/triggers/_trigger.html.haml b/app/views/projects/triggers/_trigger.html.haml
index ed68e0ed56d..9b5f63ae81a 100644
--- a/app/views/projects/triggers/_trigger.html.haml
+++ b/app/views/projects/triggers/_trigger.html.haml
@@ -2,7 +2,7 @@
   %td
     - if can?(current_user, :admin_trigger, trigger)
       %span= trigger.token
-      = clipboard_button(clipboard_text: trigger.token, title: "Copy trigger token to clipboard")
+      = clipboard_button(text: trigger.token, title: "Copy trigger token to clipboard")
     - else
       %span= trigger.short_token
 
diff --git a/app/views/shared/_clone_panel.html.haml b/app/views/shared/_clone_panel.html.haml
index 03684389742..34a4d7398bc 100644
--- a/app/views/shared/_clone_panel.html.haml
+++ b/app/views/shared/_clone_panel.html.haml
@@ -19,7 +19,7 @@
 
   = text_field_tag :project_clone, default_url_to_repo(project), class: "js-select-on-focus form-control", readonly: true
   .input-group-btn
-    = clipboard_button(clipboard_target: '#project_clone', title: "Copy URL to clipboard")
+    = clipboard_button(target: '#project_clone', title: "Copy URL to clipboard")
 
 :javascript
   $('ul.clone-options-dropdown a').on('click',function(e){
diff --git a/app/views/shared/_personal_access_tokens_table.html.haml b/app/views/shared/_personal_access_tokens_table.html.haml
index 67a49815478..ab7a2db002e 100644
--- a/app/views/shared/_personal_access_tokens_table.html.haml
+++ b/app/views/shared/_personal_access_tokens_table.html.haml
@@ -33,7 +33,7 @@
             - if impersonation
               %td.token-token-container
                 = text_field_tag 'impersonation-token-token', token.token, readonly: true, class: "form-control"
-                = clipboard_button(clipboard_text: token.token)
+                = clipboard_button(text: token.token)
             - path = impersonation ? revoke_admin_user_impersonation_token_path(token.user, token) : revoke_profile_personal_access_token_path(token)
             %td= link_to "Revoke", path, method: :put, class: "btn btn-danger pull-right", data: { confirm: "Are you sure you want to revoke this #{type} Token? This action cannot be undone." }
 - else
diff --git a/app/views/shared/issuable/_sidebar.html.haml b/app/views/shared/issuable/_sidebar.html.haml
index 92d2d93a732..2e0d6a129fb 100644
--- a/app/views/shared/issuable/_sidebar.html.haml
+++ b/app/views/shared/issuable/_sidebar.html.haml
@@ -160,13 +160,13 @@
       - project_ref = cross_project_reference(@project, issuable)
       .block.project-reference
         .sidebar-collapsed-icon.dont-change-state
-          = clipboard_button(clipboard_text: project_ref, title: "Copy reference to clipboard", placement: "left")
+          = clipboard_button(text: project_ref, title: "Copy reference to clipboard", placement: "left")
         .cross-project-reference.hide-collapsed
           %span
             Reference:
             %cite{ title: project_ref }
               = project_ref
-          = clipboard_button(clipboard_text: project_ref, title: "Copy reference to clipboard", placement: "left")
+          = clipboard_button(text: project_ref, title: "Copy reference to clipboard", placement: "left")
 
     :javascript
       gl.IssuableResource = new gl.SubbableResource('#{issuable_json_path(issuable)}');
diff --git a/app/views/shared/milestones/_sidebar.html.haml b/app/views/shared/milestones/_sidebar.html.haml
index 2810f1377b2..ccc808ff43e 100644
--- a/app/views/shared/milestones/_sidebar.html.haml
+++ b/app/views/shared/milestones/_sidebar.html.haml
@@ -122,10 +122,10 @@
     - if milestone_ref.present?
       .block.reference
         .sidebar-collapsed-icon.dont-change-state
-          = clipboard_button(clipboard_text: milestone_ref, title: "Copy reference to clipboard", placement: "left")
+          = clipboard_button(text: milestone_ref, title: "Copy reference to clipboard", placement: "left")
         .cross-project-reference.hide-collapsed
           %span
             Reference:
             %cite{ title: milestone_ref }
               = milestone_ref
-          = clipboard_button(clipboard_text: milestone_ref, title: "Copy reference to clipboard", placement: "left")
+          = clipboard_button(text: milestone_ref, title: "Copy reference to clipboard", placement: "left")
diff --git a/changelogs/unreleased/dm-copy-diff-file-title-as-gfm.yml b/changelogs/unreleased/dm-copy-diff-file-title-as-gfm.yml
new file mode 100644
index 00000000000..506883bc17d
--- /dev/null
+++ b/changelogs/unreleased/dm-copy-diff-file-title-as-gfm.yml
@@ -0,0 +1,4 @@
+---
+title: After copying a diff file or blob path, pasting it into a comment field will format it as Markdown.
+merge_request: 9876
+author: