diff --git a/ci-automation/garbage_collect.sh b/ci-automation/garbage_collect.sh
index f58ae8e952..e8dbc92c11 100644
--- a/ci-automation/garbage_collect.sh
+++ b/ci-automation/garbage_collect.sh
@@ -18,6 +18,8 @@
 # Flatcar CI automation garbage collector.
 #  This script removes development (non-official) build artifacts:
 #   - SDK tarballs, build step containers, and vendor images on buildcache
+#   - SDK containers built via Github actions (e.g. from PRs).
+#      See https://github.com/flatcar/scripts/blob/main/.github/workflows/update-sdk.yaml
 #   - tags from the scripts repository
 #
 #  Garbage collection is based on development (non-official) version tags
@@ -142,6 +144,12 @@ function _garbage_collect_impl() {
         fi
     done
 
+    echo
+    echo "########################################"
+    echo
+    echo    Running cloud garbace collector
+    echo
+
     local mantle_ref
     mantle_ref=$(cat sdk_container/.repo/manifests/mantle-container)
     docker run --pull always --rm --net host \
@@ -153,5 +161,14 @@ function _garbage_collect_impl() {
       --env VMWARE_ESX_CREDS \
       --env OPENSTACK_CREDS \
       -w /work -v "$PWD":/work "${mantle_ref}" /work/ci-automation/garbage_collect_cloud.sh
+
+    echo
+    echo "#############################################"
+    echo
+    echo    Running Github CI SDK garbace collector
+    echo
+
+    source ci-automation/garbage_collect_github_ci_sdk.sh
+    garbage_collect_github_ci
 }
 # --
diff --git a/ci-automation/garbage_collect_github_ci_sdk.sh b/ci-automation/garbage_collect_github_ci_sdk.sh
new file mode 100644
index 0000000000..2388e58db8
--- /dev/null
+++ b/ci-automation/garbage_collect_github_ci_sdk.sh
@@ -0,0 +1,99 @@
+#!/bin/bash
+#
+# Copyright (c) 2021 The Flatcar Maintainers.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# >>> This file is supposed to be SOURCED from the repository ROOT. <<<
+#
+# garbage_collect_github_ci() should be called after sourcing.
+#
+#  OPTIONAL INPUT
+#  - Number of (recent) Github SDK builds to keep. Defaults to 20.
+#  - DRY_RUN (Env variable). Set to "y" to just list what would be done but not
+#            actually purge anything.
+
+# Flatcar Github CI SDK rebuild automation garbage collector.
+#  This script removes development (non-official) SDK image builds generated via Github CI.
+#
+#  Garbage collection is based on development (non-official) SDK versions listed on
+#     https://bincache.flatcar-linux.net/containers/
+#  and following the pattern [VERSION_NUMBER]*-github-*. The newest 20 builds will be retained,
+#   all older builds will be purged (20 is the default, see OPTIONAL INPUT above).
+
+function garbage_collect_github_ci() {
+    # Run a subshell, so the traps, environment changes and global
+    # variables are not spilled into the caller.
+    (
+        set -euo pipefail
+
+        _garbage_collect_github_ci_impl "${@}"
+    )
+}
+# --
+
+function _garbage_collect_github_ci_impl() {
+    local keep="${1:-50}"
+    local dry_run="${DRY_RUN:-}"
+
+    # Example version string
+    #   <a href="./3598.0.0-nightly-20230508-2100-github-2023_05_09__08_06_54/">
+    #   <a href="./3598.0.0-nightly-20230508-2100-github-pr-12345-2023_05_09__08_06_54/">
+    local versions_detected="$(curl -s https://bincache.flatcar-linux.net/containers/ \
+                | grep -E '\<a href="\./[0-9]+\.[0-9]+.[0-9]+.+-github-.*/">' \
+                | sed 's:.*\"./\([^/]\+\)/".*:\1:' )"
+
+    # Sort versions by date. Since version numbers can differ and this would impact sort, we
+    # 1. insert a "/" between "...-github-[pr-XXX]-" and "[date]..."
+    # 2. sort with delimiter "/" and sorting key 2 (i.e. the date part)
+    # 3. remove the "/"
+   local versions_sorted="$(echo "${versions_detected}" \
+                        | sed 's/\(-github\(-pr-[0-9]*\)*-\)/\1\//' \
+                        | sort -k 2 -t / \
+                        | sed 's:/::')"
+
+    echo "######## Full list of version(s) found ########"
+    echo "${versions_sorted}" | awk '{printf "%5d %s\n", NR, $0}'
+
+    local keep="$((keep + 1))" # for tail -n+...
+    local purge_versions="$(echo "${versions_sorted}" \
+                            | tail -n+"${keep}")"
+
+    source ci-automation/ci_automation_common.sh
+    local sshcmd="$(gen_sshcmd)"
+
+    echo
+    echo "######## The following version(s) will be purged ########"
+    if [ "$dry_run" = "y" ] ; then
+        echo
+        echo "(NOTE this is just a dry run since DRY_RUN=y)"
+        echo
+    fi
+    echo "${purge_versions}" | awk -v keep="${keep}" '{if ($0 == "") next; printf "%5d %s\n", NR + keep - 1, $0}'
+    echo
+    echo
+
+    local version=""
+    for version in ${purge_versions}; do
+        echo "--------------------------------------------"
+        echo
+        echo "#### Processing version '${version}' ####"
+        echo
+
+        local rmpat="${BUILDCACHE_PATH_PREFIX}/containers/${version}/"
+
+        echo "## The following files will be removed ##"
+        $sshcmd "${BUILDCACHE_USER}@${BUILDCACHE_SERVER}" \
+            "ls -la ${rmpat} || true"
+
+        if [ "$dry_run" != "y" ] ; then
+            set -x
+            $sshcmd "${BUILDCACHE_USER}@${BUILDCACHE_SERVER}" \
+                "rm -rf ${rmpat}"
+            set +x
+        else
+            echo "## (DRY_RUN=y so not doing anything) ##"
+        fi
+    done
+}
+# --