diff --git a/app/graphql/resolvers/merge_requests_resolver.rb b/app/graphql/resolvers/merge_requests_resolver.rb
index 4761be1cf92f31b10d0310b7e8c29224001f1b3d..ebbb68611b3d0b609fc996b495208c69e214ce86 100644
--- a/app/graphql/resolvers/merge_requests_resolver.rb
+++ b/app/graphql/resolvers/merge_requests_resolver.rb
@@ -176,6 +176,13 @@ def self.accept_reviewer
       argument :reviewer_username, GraphQL::Types::String,
         required: false,
         description: 'Username of the reviewer to exclude.'
+      argument :source_branches, [GraphQL::Types::String],
+        required: false,
+        as: :source_branch,
+        description: <<~DESC
+                Array of source branch names.
+                No resolved merge requests will have one of these branches as their source.
+        DESC
     end
 
     validates mutually_exclusive: [:assignee_username, :assignee_wildcard_id]
diff --git a/doc/api/graphql/reference/index.md b/doc/api/graphql/reference/index.md
index 94e1306c5de7eca1c8305f1aa7d24b7789518240..32adfbd7065cc06d31a29c3a33239d4e8165b763 100644
--- a/doc/api/graphql/reference/index.md
+++ b/doc/api/graphql/reference/index.md
@@ -42906,6 +42906,7 @@ Defines which user roles, users, or groups can merge into a protected branch.
 | <a id="mergerequestsresolvernegatedparamsmyreactionemoji"></a>`myReactionEmoji` | [`String`](#string) | Filter by reaction emoji to exclude. |
 | <a id="mergerequestsresolvernegatedparamsreleasetag"></a>`releaseTag` | [`String`](#string) | Filter by release tag to exclude. |
 | <a id="mergerequestsresolvernegatedparamsreviewerusername"></a>`reviewerUsername` | [`String`](#string) | Username of the reviewer to exclude. |
+| <a id="mergerequestsresolvernegatedparamssourcebranches"></a>`sourceBranches` | [`[String!]`](#string) | Array of source branch names. No resolved merge requests will have one of these branches as their source. |
 
 ### `MonthSelectionInput`
 
diff --git a/spec/graphql/resolvers/merge_requests_resolver_spec.rb b/spec/graphql/resolvers/merge_requests_resolver_spec.rb
index b586e8c4f5b97e155ed2d6f78a85061fe66516f3..15f3ca47becd579d307825e3c38cb7b3ea5cf719 100644
--- a/spec/graphql/resolvers/merge_requests_resolver_spec.rb
+++ b/spec/graphql/resolvers/merge_requests_resolver_spec.rb
@@ -149,6 +149,16 @@
       end
     end
 
+    context 'with negated source branches argument' do
+      it 'excludes merge requests with given source branches from selection' do
+        mrs = [merge_request_3, merge_request_4]
+        branches = mrs.map(&:source_branch)
+        result = resolve_mr(project, not: { source_branches: branches })
+
+        expect(result).not_to include(merge_request_3, merge_request_4)
+      end
+    end
+
     context 'with target branches argument' do
       it 'takes one argument' do
         result = resolve_mr(project, target_branches: [merge_request_3.target_branch])