diff --git a/esphome/components/bluetooth_proxy/bluetooth_proxy.cpp b/esphome/components/bluetooth_proxy/bluetooth_proxy.cpp
index 98f11fac7a..a5e8ec0860 100644
--- a/esphome/components/bluetooth_proxy/bluetooth_proxy.cpp
+++ b/esphome/components/bluetooth_proxy/bluetooth_proxy.cpp
@@ -58,10 +58,15 @@ bool BluetoothProxy::parse_device(const esp32_ble_tracker::ESPBTDevice &device)
 // 16 advertisements × 80 bytes (worst case) = 1280 bytes out of ~1320 bytes usable payload
 // This achieves ~97% WiFi MTU utilization while staying under the limit
 static constexpr size_t FLUSH_BATCH_SIZE = 16;
-static std::vector<api::BluetoothLERawAdvertisement> &get_batch_buffer() {
-  static std::vector<api::BluetoothLERawAdvertisement> batch_buffer;
-  return batch_buffer;
-}
+
+namespace {
+// Batch buffer in anonymous namespace to avoid guard variable (saves 8 bytes)
+// This is initialized at program startup before any threads
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+std::vector<api::BluetoothLERawAdvertisement> batch_buffer;
+}  // namespace
+
+static std::vector<api::BluetoothLERawAdvertisement> &get_batch_buffer() { return batch_buffer; }
 
 bool BluetoothProxy::parse_devices(const esp32_ble::BLEScanResult *scan_results, size_t count) {
   if (!api::global_api_server->is_connected() || this->api_connection_ == nullptr || !this->raw_advertisements_)