diff --git a/src/dispatch/plugins/dispatch_slack/plugin.py b/src/dispatch/plugins/dispatch_slack/plugin.py
index 55320cc5e3e1..913cf2cfeaf6 100644
--- a/src/dispatch/plugins/dispatch_slack/plugin.py
+++ b/src/dispatch/plugins/dispatch_slack/plugin.py
@@ -205,8 +205,10 @@ def send_direct(
         blocks: Optional[List] = None,
         **kwargs,
     ):
-        """Sends a message directly to a user."""
+        """Sends a message directly to a user if the user exists."""
         client = create_slack_client(self.configuration)
+        if not does_user_exist(client, user):
+            return {}
         user_id = resolve_user(client, user)["id"]
 
         if not blocks:
@@ -227,8 +229,10 @@ def send_ephemeral(
         blocks: Optional[List] = None,
         **kwargs,
     ):
-        """Sends an ephemeral message to a user in a channel."""
+        """Sends an ephemeral message to a user in a channel if the user exists."""
         client = create_slack_client(self.configuration)
+        if not does_user_exist(client, user):
+            return {}
         user_id = resolve_user(client, user)["id"]
 
         if not blocks: