diff --git a/resources/testdriver.js b/resources/testdriver.js
index aee319f57571d0..57f36478c35791 100644
--- a/resources/testdriver.js
+++ b/resources/testdriver.js
@@ -1326,6 +1326,25 @@
          */
         remove_virtual_pressure_source: function(source_type, context=null) {
             return window.test_driver_internal.remove_virtual_pressure_source(source_type, context);
+        },
+
+        /**
+         * Sets which hashes are considered k-anonymous for the Protected
+         * Audience interest group with specified `owner` and `name`.
+         *
+         *  @param {String} owner - Origin of the owner of the interest group
+         *                          to modify
+         *  @param {String} name -  Name of the interest group to modify
+         *  @param {Array} hashes - An array of strings, each of which is a
+         *                          base64 ecoded hash to consider k-anonymous.
+         *
+         *  @returns {Promise} Fulfilled after the k-anonymity status for the
+         *                     specified Protected Audience interest group has
+         *                     been updated.
+         *
+         */
+        set_protected_audience_k_anonymity: function(owner, name, hashes, context = null) {
+            return window.test_driver_internal.set_protected_audience_k_anonymity(owner, name, hashes, context);
         }
     };
 
@@ -1565,6 +1584,10 @@
 
         async remove_virtual_pressure_source(source_type, context=null) {
             throw new Error("remove_virtual_pressure_source() is not implemented by testdriver-vendor.js");
+        },
+
+        async set_protected_audience_k_anonymity(owner, name, hashes, context=null) {
+            throw new Error("set_protected_audience_k_anonymity() is not implemented by testdriver-vendor.js");
         }
     };
 })();
diff --git a/tools/wptrunner/wptrunner/executors/actions.py b/tools/wptrunner/wptrunner/executors/actions.py
index 859ce8f4fa6044..86690cac2c8c70 100644
--- a/tools/wptrunner/wptrunner/executors/actions.py
+++ b/tools/wptrunner/wptrunner/executors/actions.py
@@ -511,6 +511,17 @@ def __call__(self, payload):
         source_type = payload["source_type"]
         return self.protocol.pressure.remove_virtual_pressure_source(source_type)
 
+class SetProtectedAudienceKAnonymityAction:
+    name = "set_protected_audience_k_anonymity"
+
+    def __init__(self, logger, protocol):
+        self.logger = logger
+        self.protocol = protocol
+
+    def __call__(self, payload):
+        owner, name, hashes = payload["owner"], payload["name"], payload["hashes"]
+        return self.protocol.protected_audience.set_k_anonymity(owner, name, hashes)
+
 actions = [ClickAction,
            DeleteAllCookiesAction,
            GetAllCookiesAction,
@@ -550,4 +561,5 @@ def __call__(self, payload):
            RunBounceTrackingMitigationsAction,
            CreateVirtualPressureSourceAction,
            UpdateVirtualPressureSourceAction,
-           RemoveVirtualPressureSourceAction]
+           RemoveVirtualPressureSourceAction,
+           SetProtectedAudienceKAnonymityAction]
diff --git a/tools/wptrunner/wptrunner/executors/executorwebdriver.py b/tools/wptrunner/wptrunner/executors/executorwebdriver.py
index 7513887998d6cd..303eda8286deec 100644
--- a/tools/wptrunner/wptrunner/executors/executorwebdriver.py
+++ b/tools/wptrunner/wptrunner/executors/executorwebdriver.py
@@ -45,6 +45,7 @@
                        DevicePostureProtocolPart,
                        StorageProtocolPart,
                        VirtualPressureSourceProtocolPart,
+                       ProtectedAudienceProtocolPart,
                        merge_dicts)
 
 from typing import List, Optional, Tuple
@@ -669,6 +670,13 @@ def update_virtual_pressure_source(self, source_type, sample):
     def remove_virtual_pressure_source(self, source_type):
         return self.webdriver.send_session_command("DELETE", "pressuresource/%s" % source_type)
 
+class WebDriverProtectedAudienceProtocolPart(ProtectedAudienceProtocolPart):
+    def setup(self):
+        self.webdriver = self.parent.webdriver
+
+    def set_k_anonymity(self, owner, name, hashes):
+        body = {"owner": owner, "name": name, "hashes": hashes}
+        return self.webdriver.send_session_command("POST", "protected_audience/set_k_anonymity", body)
 
 class WebDriverProtocol(Protocol):
     enable_bidi = False
@@ -693,7 +701,8 @@ class WebDriverProtocol(Protocol):
                   WebDriverVirtualSensorPart,
                   WebDriverDevicePostureProtocolPart,
                   WebDriverStorageProtocolPart,
-                  WebDriverVirtualPressureSourceProtocolPart]
+                  WebDriverVirtualPressureSourceProtocolPart,
+                  WebDriverProtectedAudienceProtocolPart]
 
     def __init__(self, executor, browser, capabilities, **kwargs):
         super().__init__(executor, browser)
diff --git a/tools/wptrunner/wptrunner/executors/protocol.py b/tools/wptrunner/wptrunner/executors/protocol.py
index 19d5b49d2b7fb4..59fadb9c7edb71 100644
--- a/tools/wptrunner/wptrunner/executors/protocol.py
+++ b/tools/wptrunner/wptrunner/executors/protocol.py
@@ -982,3 +982,13 @@ def update_virtual_pressure_source(self, source_type, sample):
     @abstractmethod
     def remove_virtual_pressure_source(self, source_type):
         pass
+
+class ProtectedAudienceProtocolPart(ProtocolPart):
+    """Protocol part for Protected Audiences"""
+    __metaclass__ = ABCMeta
+
+    name = "protected_audience"
+
+    @abstractmethod
+    def set_k_anonymity(self, owner, name, hashes):
+      pass
diff --git a/tools/wptrunner/wptrunner/testdriver-extra.js b/tools/wptrunner/wptrunner/testdriver-extra.js
index 2dd9a70c829895..9beac84c0105c5 100644
--- a/tools/wptrunner/wptrunner/testdriver-extra.js
+++ b/tools/wptrunner/wptrunner/testdriver-extra.js
@@ -439,4 +439,10 @@
     window.test_driver_internal.remove_virtual_pressure_source = function(source_type, context=null) {
         return create_context_action("remove_virtual_pressure_source", context, {source_type});
     };
+
+    window.test_driver_internal.set_protected_audience_k_anonymity = function(
+        owner, name, hashes, context) {
+      return create_context_action(
+          'set_protected_audience_k_anonymity', context, {owner, name, hashes});
+    }
 })();