diff --git a/.github/workflows/blockifier_ci.yml b/.github/workflows/blockifier_ci.yml
index bb57415f38..eaf9f485b9 100644
--- a/.github/workflows/blockifier_ci.yml
+++ b/.github/workflows/blockifier_ci.yml
@@ -32,6 +32,11 @@ on:
       - 'scripts/install_build_tools.sh'
       - 'scripts/sequencer-ci.Dockerfile'
 
+# On PR events, cancel existing CI runs on this same PR for this workflow.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event.name == 'pull_request' }}
+
 jobs:
   featureless-build:
     runs-on: starkware-ubuntu-20-04-medium
diff --git a/.github/workflows/blockifier_compiled_cairo.yml b/.github/workflows/blockifier_compiled_cairo.yml
index 83e57f82d0..d5fcfa49ea 100644
--- a/.github/workflows/blockifier_compiled_cairo.yml
+++ b/.github/workflows/blockifier_compiled_cairo.yml
@@ -21,6 +21,11 @@ on:
       - 'crates/blockifier/feature_contracts/cairo0/**'
       - 'crates/blockifier/tests/requirements.txt'
 
+# On PR events, cancel existing CI runs on this same PR for this workflow.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event.name == 'pull_request' }}
+
 jobs:
   verify_cairo_file_dependencies:
     runs-on: starkware-ubuntu-20-04-medium
diff --git a/.github/workflows/committer_ci.yml b/.github/workflows/committer_ci.yml
index 13efff6b17..34691e6b98 100644
--- a/.github/workflows/committer_ci.yml
+++ b/.github/workflows/committer_ci.yml
@@ -30,6 +30,11 @@ on:
       - 'crates/starknet_committer/**'
       - 'crates/starknet_patricia/**'
 
+# On PR events, cancel existing CI runs on this same PR for this workflow.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event.name == 'pull_request' }}
+
 jobs:
   run-regression-tests:
     runs-on: starkware-ubuntu-latest-small
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 395ea506ba..c3b82869f2 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -16,6 +16,11 @@ on:
       - auto_merge_enabled
       - edited
 
+# On PR events, cancel existing CI runs on this same PR for this workflow.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event.name == 'pull_request' }}
+
 jobs:
   commitlint:
     runs-on: starkware-ubuntu-latest-small
diff --git a/.github/workflows/merge_paths_ci.yml b/.github/workflows/merge_paths_ci.yml
index 456a1bd694..ebe68a84cc 100644
--- a/.github/workflows/merge_paths_ci.yml
+++ b/.github/workflows/merge_paths_ci.yml
@@ -28,6 +28,11 @@ on:
       - 'scripts/merge_paths_test.py'
       - 'scripts/merge_status.py'
 
+# On PR events, cancel existing CI runs on this same PR for this workflow.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event.name == 'pull_request' }}
+
 jobs:
   merge-paths-test:
     runs-on: starkware-ubuntu-latest-small
diff --git a/.github/workflows/papyrus_ci.yml b/.github/workflows/papyrus_ci.yml
index 5141e6c4df..15d8b0b6a9 100644
--- a/.github/workflows/papyrus_ci.yml
+++ b/.github/workflows/papyrus_ci.yml
@@ -33,6 +33,11 @@ on:
   merge_group:
     types: [checks_requested]
 
+# On PR events, cancel existing CI runs on this same PR for this workflow.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event.name == 'pull_request' }}
+
 env:
   PROTOC_VERSION: v25.1
 
diff --git a/.github/workflows/papyrus_docker-publish.yml b/.github/workflows/papyrus_docker-publish.yml
index 760b379ec8..7276ab779e 100644
--- a/.github/workflows/papyrus_docker-publish.yml
+++ b/.github/workflows/papyrus_docker-publish.yml
@@ -14,6 +14,11 @@ on:
       - '.github/workflows/papyrus_docker-publish.yml'
       - 'crates/papyrus**/**'
 
+# On PR events, cancel existing CI runs on this same PR for this workflow.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event.name == 'pull_request' }}
+
 env:
   REGISTRY: ghcr.io
   REPO_NAME: ${{ github.repository }}