diff --git a/.github/workflows/ci_linux_arm64_clang.yml b/.github/workflows/ci_linux_arm64_clang.yml
index 65bc19b19d03..00fb531ff528 100644
--- a/.github/workflows/ci_linux_arm64_clang.yml
+++ b/.github/workflows/ci_linux_arm64_clang.yml
@@ -25,6 +25,7 @@ concurrency:
 
 jobs:
   linux_arm64_clang:
+    if: ${{ github.repository_owner == 'iree-org' }}
     # See https://gitlab.arm.com/tooling/gha-runner-docs
     runs-on: ah-ubuntu_22_04-c7g_4x-50
     container:
diff --git a/.github/workflows/ci_linux_x64_clang_debug.yml b/.github/workflows/ci_linux_x64_clang_debug.yml
index 9f2e629b8656..c57319a38b5d 100644
--- a/.github/workflows/ci_linux_x64_clang_debug.yml
+++ b/.github/workflows/ci_linux_x64_clang_debug.yml
@@ -27,7 +27,8 @@ jobs:
   # This may run out of memory / disk space on standard GitHub-hosted runners,
   # so run on self-hosted CPU build runners instead.
   linux_x64_clang_debug:
-    runs-on: azure-linux-scale
+    if: ${{ github.repository_owner == 'iree-org' || github.event_name != 'schedule' }}
+    runs-on: ${{ github.repository_owner == 'iree-org' && 'azure-linux-scale' ||  'ubuntu-24.04'  }}
     container: ghcr.io/iree-org/cpubuilder_ubuntu_jammy@sha256:78a558b999b230f7e1da376639e14b44f095f30f1777d6a272ba48c0bbdd4ccb
     defaults:
       run:
diff --git a/.github/workflows/ci_linux_x64_clang_tsan.yml b/.github/workflows/ci_linux_x64_clang_tsan.yml
index 7ababb08c4fa..6d6562c888f7 100644
--- a/.github/workflows/ci_linux_x64_clang_tsan.yml
+++ b/.github/workflows/ci_linux_x64_clang_tsan.yml
@@ -24,12 +24,9 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  setup:
-    uses: ./.github/workflows/setup.yml
-
   linux_x64_clang_tsan:
-    needs: setup
-    runs-on: azure-linux-scale
+    if: ${{ github.repository_owner == 'iree-org' || github.event_name != 'schedule' }}
+    runs-on: ${{ github.repository_owner == 'iree-org' && 'azure-linux-scale' ||  'ubuntu-24.04'  }}
     container:
       image: ghcr.io/iree-org/cpubuilder_ubuntu_jammy@sha256:78a558b999b230f7e1da376639e14b44f095f30f1777d6a272ba48c0bbdd4ccb
       # TSan in particular needs some settings that this option includes:
diff --git a/.github/workflows/ci_windows_x64_msvc.yml b/.github/workflows/ci_windows_x64_msvc.yml
index d309732bb272..09ebea36a215 100644
--- a/.github/workflows/ci_windows_x64_msvc.yml
+++ b/.github/workflows/ci_windows_x64_msvc.yml
@@ -21,6 +21,7 @@ concurrency:
 
 jobs:
   windows_x64_msvc:
+    if: ${{ github.repository_owner == 'iree-org' || github.event_name != 'schedule' }}
     runs-on: azure-windows-scale
     env:
       BASE_BUILD_DIR_POWERSHELL: C:\mnt\azure\b
diff --git a/.github/workflows/samples.yml b/.github/workflows/samples.yml
index 576ebe623fbf..d13221705197 100644
--- a/.github/workflows/samples.yml
+++ b/.github/workflows/samples.yml
@@ -28,6 +28,7 @@ concurrency:
 
 jobs:
   colab:
+    if: ${{ github.repository_owner == 'iree-org' || github.event_name != 'schedule' }}
     runs-on: ubuntu-24.04
     steps:
       - name: "Checking out repository"
@@ -40,6 +41,7 @@ jobs:
         run: ./samples/colab/test_notebooks.py
 
   samples:
+    if: ${{ github.repository_owner == 'iree-org' || github.event_name != 'schedule' }}
     runs-on: ubuntu-24.04
     env:
       CC: clang
@@ -59,6 +61,7 @@ jobs:
         run: ./build_tools/testing/test_samples.sh
 
   web:
+    if: ${{ github.repository_owner == 'iree-org' || github.event_name != 'schedule' }}
     runs-on: ubuntu-24.04
     env:
       VENV_DIR: ${{ github.workspace }}/.venv
diff --git a/.github/workflows/schedule_candidate_release.yml b/.github/workflows/schedule_candidate_release.yml
index fb2b5facdc8d..d9b247350dcd 100644
--- a/.github/workflows/schedule_candidate_release.yml
+++ b/.github/workflows/schedule_candidate_release.yml
@@ -14,6 +14,7 @@ on:
 
 jobs:
   tag_release:
+    if: ${{ github.repository_owner == 'iree-org' || github.event_name != 'schedule' }}
     name: "Tag candidate release"
     runs-on: ubuntu-24.04
     steps: