diff --git a/esphome/components/adc/__init__.py b/esphome/components/adc/__init__.py
index ba72951777..0b6ee145f2 100644
--- a/esphome/components/adc/__init__.py
+++ b/esphome/components/adc/__init__.py
@@ -5,6 +5,10 @@ from esphome.const import CONF_ANALOG, CONF_INPUT
 
 from esphome.core import CORE
 from esphome.components.esp32 import get_esp32_variant
+from esphome.const import (
+    PLATFORM_ESP8266,
+    PLATFORM_RP2040,
+)
 from esphome.components.esp32.const import (
     VARIANT_ESP32,
     VARIANT_ESP32C2,
@@ -143,7 +147,7 @@ ESP32_VARIANT_ADC2_PIN_TO_CHANNEL = {
 
 def validate_adc_pin(value):
     if str(value).upper() == "VCC":
-        return cv.only_on_esp8266("VCC")
+        return cv.only_on([PLATFORM_ESP8266, PLATFORM_RP2040])("VCC")
 
     if str(value).upper() == "TEMPERATURE":
         return cv.only_on_rp2040("TEMPERATURE")
diff --git a/esphome/components/adc/adc_sensor.cpp b/esphome/components/adc/adc_sensor.cpp
index 0642cd7f3f..e69e6b9313 100644
--- a/esphome/components/adc/adc_sensor.cpp
+++ b/esphome/components/adc/adc_sensor.cpp
@@ -12,6 +12,9 @@ ADC_MODE(ADC_VCC)
 #endif
 
 #ifdef USE_RP2040
+#ifdef CYW43_USES_VSYS_PIN
+#include "pico/cyw43_arch.h"
+#endif
 #include <hardware/adc.h>
 #endif
 
@@ -123,13 +126,19 @@ void ADCSensor::dump_config() {
     }
   }
 #endif  // USE_ESP32
+
 #ifdef USE_RP2040
   if (this->is_temperature_) {
     ESP_LOGCONFIG(TAG, "  Pin: Temperature");
   } else {
+#ifdef USE_ADC_SENSOR_VCC
+    ESP_LOGCONFIG(TAG, "  Pin: VCC");
+#else
     LOG_PIN("  Pin: ", pin_);
+#endif  // USE_ADC_SENSOR_VCC
   }
-#endif
+#endif  // USE_RP2040
+
   LOG_UPDATE_INTERVAL(this);
 }
 
@@ -238,7 +247,20 @@ float ADCSensor::sample() {
     delay(1);
     adc_select_input(4);
   } else {
-    uint8_t pin = this->pin_->get_pin();
+    uint8_t pin;
+#ifdef USE_ADC_SENSOR_VCC
+#ifdef CYW43_USES_VSYS_PIN
+    // Measuring VSYS on Raspberry Pico W needs to be wrapped with
+    // `cyw43_thread_enter()`/`cyw43_thread_exit()` as discussed in
+    // https://github.com/raspberrypi/pico-sdk/issues/1222, since Wifi chip and
+    // VSYS ADC both share GPIO29
+    cyw43_thread_enter();
+#endif  // CYW43_USES_VSYS_PIN
+    pin = PICO_VSYS_PIN;
+#else
+    pin = this->pin_->get_pin();
+#endif  // USE_ADC_SENSOR_VCC
+
     adc_gpio_init(pin);
     adc_select_input(pin - 26);
   }
@@ -246,11 +268,23 @@ float ADCSensor::sample() {
   int32_t raw = adc_read();
   if (this->is_temperature_) {
     adc_set_temp_sensor_enabled(false);
+  } else {
+#ifdef USE_ADC_SENSOR_VCC
+#ifdef CYW43_USES_VSYS_PIN
+    cyw43_thread_exit();
+#endif  // CYW43_USES_VSYS_PIN
+#endif  // USE_ADC_SENSOR_VCC
   }
+
   if (output_raw_) {
     return raw;
   }
-  return raw * 3.3f / 4096.0f;
+  float coeff = 1.0;
+#ifdef USE_ADC_SENSOR_VCC
+  // As per Raspberry Pico (W) datasheet (section 2.1) the VSYS/3 is measured
+  coeff = 3.0;
+#endif  // USE_ADC_SENSOR_VCC
+  return raw * 3.3f / 4096.0f * coeff;
 }
 #endif
 
diff --git a/tests/test6.yaml b/tests/test6.yaml
index f048a4fa14..3d6a1ceb1f 100644
--- a/tests/test6.yaml
+++ b/tests/test6.yaml
@@ -62,3 +62,6 @@ switch:
 sensor:
   - platform: internal_temperature
     name: Internal Temperature
+  - platform: adc
+    pin: VCC
+    name: VSYS