diff --git a/script/hassfest/quality_scale.py b/script/hassfest/quality_scale.py
index 24c98807936..734c6d57faf 100644
--- a/script/hassfest/quality_scale.py
+++ b/script/hassfest/quality_scale.py
@@ -20,6 +20,7 @@ from .quality_scale_validation import (
     discovery,
     reauthentication_flow,
     reconfiguration_flow,
+    runtime_data,
     strict_typing,
     unique_config_entry,
 )
@@ -52,7 +53,7 @@ ALL_RULES = [
     Rule("entity-event-setup", ScaledQualityScaleTiers.BRONZE),
     Rule("entity-unique-id", ScaledQualityScaleTiers.BRONZE),
     Rule("has-entity-name", ScaledQualityScaleTiers.BRONZE),
-    Rule("runtime-data", ScaledQualityScaleTiers.BRONZE),
+    Rule("runtime-data", ScaledQualityScaleTiers.BRONZE, runtime_data),
     Rule("test-before-configure", ScaledQualityScaleTiers.BRONZE),
     Rule("test-before-setup", ScaledQualityScaleTiers.BRONZE),
     Rule("unique-config-entry", ScaledQualityScaleTiers.BRONZE, unique_config_entry),
diff --git a/script/hassfest/quality_scale_validation/runtime_data.py b/script/hassfest/quality_scale_validation/runtime_data.py
new file mode 100644
index 00000000000..765db43d1e3
--- /dev/null
+++ b/script/hassfest/quality_scale_validation/runtime_data.py
@@ -0,0 +1,53 @@
+"""Enforce that the integration uses ConfigEntry.runtime_data to store runtime data.
+
+https://developers.home-assistant.io/docs/core/integration-quality-scale/rules/runtime-data
+"""
+
+import ast
+
+from script.hassfest.model import Integration
+
+
+def _sets_runtime_data(
+    async_setup_entry_function: ast.AsyncFunctionDef, config_entry_argument: ast.arg
+) -> bool:
+    """Check that `entry.runtime` gets set within `async_setup_entry`."""
+    for node in ast.walk(async_setup_entry_function):
+        if (
+            isinstance(node, ast.Attribute)
+            and isinstance(node.value, ast.Name)
+            and node.value.id == config_entry_argument.arg
+            and node.attr == "runtime_data"
+            and isinstance(node.ctx, ast.Store)
+        ):
+            return True
+    return False
+
+
+def _get_setup_entry_function(module: ast.Module) -> ast.AsyncFunctionDef | None:
+    """Get async_setup_entry function."""
+    for item in module.body:
+        if isinstance(item, ast.AsyncFunctionDef) and item.name == "async_setup_entry":
+            return item
+    return None
+
+
+def validate(integration: Integration) -> list[str] | None:
+    """Validate correct use of ConfigEntry.runtime_data."""
+    init_file = integration.path / "__init__.py"
+    init = ast.parse(init_file.read_text())
+
+    # Should not happen, but better to be safe
+    if not (async_setup_entry := _get_setup_entry_function(init)):
+        return [f"Could not find `async_setup_entry` in {init_file}"]
+    if len(async_setup_entry.args.args) != 2:
+        return [f"async_setup_entry has incorrect signature in {init_file}"]
+    config_entry_argument = async_setup_entry.args.args[1]
+
+    if not _sets_runtime_data(async_setup_entry, config_entry_argument):
+        return [
+            "Integration does not set entry.runtime_data in async_setup_entry"
+            f"({init_file})"
+        ]
+
+    return None