diff --git a/esphome/components/api/api_connection.cpp b/esphome/components/api/api_connection.cpp
index a2050ec6e5..0804985cc5 100644
--- a/esphome/components/api/api_connection.cpp
+++ b/esphome/components/api/api_connection.cpp
@@ -2075,6 +2075,9 @@ uint16_t APIConnection::dispatch_message_(const DeferredBatch::BatchItem &item,
 #ifdef USE_EVENT
   // Events need aux_data_index to look up event type from entity
   if (item.message_type == EventResponse::MESSAGE_TYPE) {
+    // Skip if aux_data_index is invalid (should never happen in normal operation)
+    if (item.aux_data_index == DeferredBatch::AUX_DATA_UNUSED)
+      return 0;
     auto *event = static_cast<event::Event *>(item.entity);
     return try_send_event_response(event, StringRef::from_maybe_nullptr(event->get_event_type(item.aux_data_index)),
                                    this, remaining_size, is_single);