diff --git a/CHANGELOG b/CHANGELOG
index 2c88d2b2ac9..48eaa328f23 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -93,6 +93,7 @@ v 8.13.0 (unreleased)
   - Ability to batch assign issues relating to a merge request to the author. !5725 (jamedjo)
   - Changed Slack service user referencing from full name to username (Sebastian Poxhofer)
   - Retouch environments list and deployments list
+  - Add multiple command support for all label related slash commands !6780 (barthc)
   - Add Container Registry on/off status to Admin Area !6638 (the-undefined)
   - Allow empty merge requests !6384 (Artem Sidorenko)
   - Grouped pipeline dropdown is a scrollable container
diff --git a/app/services/slash_commands/interpret_service.rb b/app/services/slash_commands/interpret_service.rb
index 1725a30fae5..e4ae3dec8aa 100644
--- a/app/services/slash_commands/interpret_service.rb
+++ b/app/services/slash_commands/interpret_service.rb
@@ -122,7 +122,12 @@ module SlashCommands
     command :label do |labels_param|
       label_ids = find_label_ids(labels_param)
 
-      @updates[:add_label_ids] = label_ids unless label_ids.empty?
+      if label_ids.any?
+        @updates[:add_label_ids] ||= []
+        @updates[:add_label_ids] += label_ids
+
+        @updates[:add_label_ids].uniq!
+      end
     end
 
     desc 'Remove all or specific label(s)'
@@ -136,7 +141,12 @@ module SlashCommands
       if labels_param.present?
         label_ids = find_label_ids(labels_param)
 
-        @updates[:remove_label_ids] = label_ids unless label_ids.empty?
+        if label_ids.any?
+          @updates[:remove_label_ids] ||= []
+          @updates[:remove_label_ids] += label_ids
+
+          @updates[:remove_label_ids].uniq!
+        end
       else
         @updates[:label_ids] = []
       end
@@ -152,7 +162,12 @@ module SlashCommands
     command :relabel do |labels_param|
       label_ids = find_label_ids(labels_param)
 
-      @updates[:label_ids] = label_ids unless label_ids.empty?
+      if label_ids.any?
+        @updates[:label_ids] ||= []
+        @updates[:label_ids] += label_ids
+
+        @updates[:label_ids].uniq!
+      end
     end
 
     desc 'Add a todo'
diff --git a/spec/services/slash_commands/interpret_service_spec.rb b/spec/services/slash_commands/interpret_service_spec.rb
index ae4d286d250..b57e338b782 100644
--- a/spec/services/slash_commands/interpret_service_spec.rb
+++ b/spec/services/slash_commands/interpret_service_spec.rb
@@ -86,6 +86,25 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
 
+    shared_examples 'multiple label command' do
+      it 'fetches label ids and populates add_label_ids if content contains multiple /label' do
+        bug # populate the label
+        inprogress # populate the label
+        _, updates = service.execute(content, issuable)
+
+        expect(updates).to eq(add_label_ids: [inprogress.id, bug.id])
+      end
+    end
+
+    shared_examples 'multiple label with same argument' do
+      it 'prevents duplicate label ids and populates add_label_ids if content contains multiple /label' do
+        inprogress # populate the label
+        _, updates = service.execute(content, issuable)
+
+        expect(updates).to eq(add_label_ids: [inprogress.id])
+      end
+    end
+
     shared_examples 'unlabel command' do
       it 'fetches label ids and populates remove_label_ids if content contains /unlabel' do
         issuable.update(label_ids: [inprogress.id]) # populate the label
@@ -95,6 +114,15 @@ describe SlashCommands::InterpretService, services: true do
       end
     end
 
+    shared_examples 'multiple unlabel command' do
+      it 'fetches label ids and populates remove_label_ids if content contains  mutiple /unlabel' do
+        issuable.update(label_ids: [inprogress.id, bug.id]) # populate the label
+        _, updates = service.execute(content, issuable)
+
+        expect(updates).to eq(remove_label_ids: [inprogress.id, bug.id])
+      end
+    end
+
     shared_examples 'unlabel command with no argument' do
       it 'populates label_ids: [] if content contains /unlabel with no arguments' do
         issuable.update(label_ids: [inprogress.id]) # populate the label
@@ -285,6 +313,16 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { merge_request }
     end
 
+    it_behaves_like 'multiple label command' do
+      let(:content) { %(/label ~"#{inprogress.title}" \n/label ~#{bug.title}) }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'multiple label with same argument' do
+      let(:content) { %(/label ~"#{inprogress.title}" \n/label ~#{inprogress.title}) }
+      let(:issuable) { issue }
+    end	
+
     it_behaves_like 'unlabel command' do
       let(:content) { %(/unlabel ~"#{inprogress.title}") }
       let(:issuable) { issue }
@@ -295,6 +333,11 @@ describe SlashCommands::InterpretService, services: true do
       let(:issuable) { merge_request }
     end
 
+    it_behaves_like 'multiple unlabel command' do
+      let(:content) { %(/unlabel ~"#{inprogress.title}" \n/unlabel ~#{bug.title}) }
+      let(:issuable) { issue }
+    end
+
     it_behaves_like 'unlabel command with no argument' do
       let(:content) { %(/unlabel) }
       let(:issuable) { issue }