diff --git a/esphome/components/api/api_connection.cpp b/esphome/components/api/api_connection.cpp
index 2b97d7a759..39ffc279f1 100644
--- a/esphome/components/api/api_connection.cpp
+++ b/esphome/components/api/api_connection.cpp
@@ -1752,10 +1752,10 @@ void APIConnection::complete_authentication_() {
 bool APIConnection::send_hello_response_(const HelloRequest &msg) {
   // Copy client name with truncation if needed (set_client_name handles truncation)
   this->helper_->set_client_name(msg.client_info.c_str(), msg.client_info.size());
-  this->client_api_version_major_ = msg.api_version_major;
-  this->client_api_version_minor_ = msg.api_version_minor;
+  this->client_api_version_major_ = static_cast<uint8_t>(std::min<uint32_t>(msg.api_version_major, 255));
+  this->client_api_version_minor_ = static_cast<uint8_t>(std::min<uint32_t>(msg.api_version_minor, 255));
   char peername[socket::SOCKADDR_STR_LEN];
-  ESP_LOGV(TAG, "Hello from client: '%s' | %s | API Version %" PRIu16 ".%" PRIu16, this->helper_->get_client_name(),
+  ESP_LOGV(TAG, "Hello from client: '%s' | %s | API Version %u.%u", this->helper_->get_client_name(),
            this->helper_->get_peername_to(peername), this->client_api_version_major_, this->client_api_version_minor_);
 
   HelloResponse resp;
diff --git a/esphome/components/api/api_connection.h b/esphome/components/api/api_connection.h
index a0a814243a..fb2d473fb9 100644
--- a/esphome/components/api/api_connection.h
+++ b/esphome/components/api/api_connection.h
@@ -757,13 +757,15 @@ class APIConnection final : public APIServerConnectionBase {
 #endif
   } flags_{};  // 2 bytes total
 
-  // 2-byte types immediately after flags_ (no padding between them)
-  uint16_t client_api_version_major_{0};
-  uint16_t client_api_version_minor_{0};
+  // 2-byte type immediately after flags_ (no padding between them)
   uint16_t batch_message_type_{0};  // Current message type during batch encoding
   // 1-byte types to fill remaining space before next 4-byte boundary
+  // Client API versions are clamped to 255 on receive (see send_hello_response_)
+  uint8_t client_api_version_major_{0};
+  uint8_t client_api_version_minor_{0};
   ActiveIterator active_iterator_{ActiveIterator::NONE};
-  // Total: 2 (flags) + 2 + 2 + 2 + 1 = 9 bytes
+  // Total: 2 (flags) + 2 + 1 + 1 + 1 + 1 (batch_header_size_ below) = 8 bytes,
+  // aligned to 4-byte boundary
 
   // Actual header size used by encode_to_buffer for the current message.
   // Read by process_batch_multi_ to pass into MessageInfo.