diff --git a/esphome/components/api/api_frame_helper.cpp b/esphome/components/api/api_frame_helper.cpp
index 06ca14411c..566e530a43 100644
--- a/esphome/components/api/api_frame_helper.cpp
+++ b/esphome/components/api/api_frame_helper.cpp
@@ -634,8 +634,8 @@ APIError APINoiseFrameHelper::write_protobuf_packets(ProtoWriteBuffer buffer, co
   }
 
   std::vector<uint8_t> *raw_buffer = buffer.get_buffer();
-  std::vector<struct iovec> iovs;
-  iovs.reserve(packets.size());
+  this->reusable_iovs_.clear();
+  this->reusable_iovs_.reserve(packets.size());
 
   // We need to encrypt each packet in place
   for (const auto &packet : packets) {
@@ -682,11 +682,11 @@ APIError APINoiseFrameHelper::write_protobuf_packets(ProtoWriteBuffer buffer, co
     struct iovec iov;
     iov.iov_base = buf_start;
     iov.iov_len = 3 + mbuf.size;  // indicator + size + encrypted data
-    iovs.push_back(iov);
+    this->reusable_iovs_.push_back(iov);
   }
 
   // Send all encrypted packets in one writev call
-  return this->write_raw_(iovs.data(), iovs.size());
+  return this->write_raw_(this->reusable_iovs_.data(), this->reusable_iovs_.size());
 }
 
 APIError APINoiseFrameHelper::write_frame_(const uint8_t *data, uint16_t len) {
@@ -1049,8 +1049,8 @@ APIError APIPlaintextFrameHelper::write_protobuf_packets(ProtoWriteBuffer buffer
   }
 
   std::vector<uint8_t> *raw_buffer = buffer.get_buffer();
-  std::vector<struct iovec> iovs;
-  iovs.reserve(packets.size());
+  this->reusable_iovs_.clear();
+  this->reusable_iovs_.reserve(packets.size());
 
   for (const auto &packet : packets) {
     uint16_t type = packet.message_type;
@@ -1099,11 +1099,11 @@ APIError APIPlaintextFrameHelper::write_protobuf_packets(ProtoWriteBuffer buffer
     struct iovec iov;
     iov.iov_base = buf_start + header_offset;
     iov.iov_len = total_header_len + payload_len;
-    iovs.push_back(iov);
+    this->reusable_iovs_.push_back(iov);
   }
 
   // Send all packets in one writev call
-  return write_raw_(iovs.data(), iovs.size());
+  return write_raw_(this->reusable_iovs_.data(), this->reusable_iovs_.size());
 }
 
 uint8_t APIPlaintextFrameHelper::calculate_header_footer_size(uint16_t message_type, uint16_t payload_len) {
diff --git a/esphome/components/api/api_frame_helper.h b/esphome/components/api/api_frame_helper.h
index 1dbe0ede8e..b5bcfbbfde 100644
--- a/esphome/components/api/api_frame_helper.h
+++ b/esphome/components/api/api_frame_helper.h
@@ -175,6 +175,9 @@ class APIFrameHelper {
   uint8_t frame_header_padding_{0};
   uint8_t frame_footer_size_{0};
 
+  // Reusable IOV array for write_protobuf_packets to avoid repeated allocations
+  std::vector<struct iovec> reusable_iovs_;
+
   // Receive buffer for reading frame data
   std::vector<uint8_t> rx_buf_;
   uint16_t rx_buf_len_ = 0;