diff --git a/esphome/components/uart/uart_component_esp_idf.h b/esphome/components/uart/uart_component_esp_idf.h
index d9297bfa34a..3b8603f2ac2 100644
--- a/esphome/components/uart/uart_component_esp_idf.h
+++ b/esphome/components/uart/uart_component_esp_idf.h
@@ -37,6 +37,12 @@ class IDFUARTComponent final : public UARTComponent, public Component {
 
   uint8_t get_hw_serial_number() { return this->uart_num_; }
 
+  /// Discard everything received so far: the peek cache and the driver's RX buffer.
+  void flush_input() {
+    this->has_peek_ = false;
+    uart_flush_input(this->uart_num_);
+  }
+
   /**
    * Load the UART with the current settings.
    * @param dump_config (Optional, default `true`): True for displaying new settings or
diff --git a/esphome/components/uart_mux/uart_mux.cpp b/esphome/components/uart_mux/uart_mux.cpp
index df2ee5ccf59..953e81d5337 100644
--- a/esphome/components/uart_mux/uart_mux.cpp
+++ b/esphome/components/uart_mux/uart_mux.cpp
@@ -2,8 +2,6 @@
 #include "uart_mux.h"
 #include "esphome/core/log.h"
 
-#include "driver/uart.h"
-
 namespace esphome::uart_mux {
 
 static const char *const TAG = "uart_mux";
@@ -36,7 +34,7 @@ void UARTMux::loop() {
     return;
   }
   // Bytes that arrived during the hand-off belong to neither owner.
-  this->flush_input_();
+  this->uart_->flush_input();
   this->route_ = Route::ROUTE_LOCAL;
   ESP_LOGD(TAG, "UART routed to local consumers");
   this->disable_loop();
@@ -97,7 +95,7 @@ void UARTMux::select_bridge() {
   // uart_read_bytes() on this port, and nothing local has run, so flush only a
   // completed hand-off.
   if (this->route_ == Route::ROUTE_LOCAL) {
-    this->flush_input_();
+    this->uart_->flush_input();
   }
   this->route_ = Route::ROUTE_BRIDGE;
   ESP_LOGD(TAG, "UART routed to bridge");
@@ -105,16 +103,6 @@ void UARTMux::select_bridge() {
   this->disable_loop();
 }
 
-void UARTMux::flush_input_() {
-  // Drain the UART component's one-byte peek cache first: the driver flush does not
-  // clear it, and draining afterwards could discard a freshly arrived byte instead.
-  uint8_t discard;
-  if (this->uart_->available() > 0) {
-    this->uart_->read_byte(&discard);
-  }
-  uart_flush_input(static_cast<uart_port_t>(this->uart_->get_hw_serial_number()));
-}
-
 void UARTMux::write_array(const uint8_t *data, size_t len) {
   if (!this->is_local()) {
     ESP_LOGV(TAG, "Dropping %zu bytes: UART routed to bridge", len);
diff --git a/esphome/components/uart_mux/uart_mux.h b/esphome/components/uart_mux/uart_mux.h
index 1eb23747142..8e32a166434 100644
--- a/esphome/components/uart_mux/uart_mux.h
+++ b/esphome/components/uart_mux/uart_mux.h
@@ -66,7 +66,6 @@ class UARTMux final : public uart::UARTComponent, public Component {
   };
 
   void check_logger_conflict() override {}
-  void flush_input_();
   // Publish settings_ through the UARTComponent getters.
   void apply_settings_();