diff --git a/overcloud.j2.yaml b/overcloud.j2.yaml
index 6f506e47e5..1398a523c0 100644
--- a/overcloud.j2.yaml
+++ b/overcloud.j2.yaml
@@ -238,6 +238,11 @@ parameters:
     description: >
       List of server hostnames to blacklist from any triggered deployments.
 
+  GlobalConfigExtraMapData:
+    type: json
+    default: {}
+    description: Map of extra global_config_settings data to set on each node.
+
 {% for role in roles %}
 {%- if role.deprecated_param_scheduler_hints is defined or role.deprecated_param_extraconfig is defined %}
 {%- if not parameter_groups_defined|default(false) %}
@@ -449,6 +454,7 @@ resources:
       type: json
       value:
         map_merge:
+          - get_param: GlobalConfigExtraMapData
           - get_attr: [{{role.name}}ServiceChainRoleData, value, config_settings]
           {% for r in roles %}
           - get_attr: [{{r.name}}ServiceChainRoleData, value, global_config_settings]
diff --git a/releasenotes/notes/add-GlobalConfigExtraMapData-793757a2b767abe3.yaml b/releasenotes/notes/add-GlobalConfigExtraMapData-793757a2b767abe3.yaml
new file mode 100644
index 0000000000..27e7da035a
--- /dev/null
+++ b/releasenotes/notes/add-GlobalConfigExtraMapData-793757a2b767abe3.yaml
@@ -0,0 +1,5 @@
+---
+features:
+  - Adds a new GlobalConfigExtraMapData parameter that can be used to inject
+    global_config_settings hieradata into the deployment. Any values generated
+    in the stack will override those passed in by the parameter value.