diff --git a/libraries/AP_Baro/AP_Baro.cpp b/libraries/AP_Baro/AP_Baro.cpp
index 7bb6b294f2..88d1afb84f 100644
--- a/libraries/AP_Baro/AP_Baro.cpp
+++ b/libraries/AP_Baro/AP_Baro.cpp
@@ -34,7 +34,6 @@
 #include "AP_Baro_BMP085.h"
 #include "AP_Baro_BMP280.h"
 #include "AP_Baro_SPL06.h"
-#include "AP_Baro_HIL.h"
 #include "AP_Baro_KellerLD.h"
 #include "AP_Baro_MS5611.h"
 #include "AP_Baro_ICM20789.h"
@@ -423,9 +422,6 @@ float AP_Baro::get_air_density_ratio(void)
 // note that this relies on read() being called regularly to get new data
 float AP_Baro::get_climb_rate(void)
 {
-    if (_hil.have_alt) {
-        return _hil.climb_rate;
-    }
     // we use a 7 point derivative filter on the climb rate. This seems
     // to produce somewhat reasonable results on real hardware
     return _climb_rate_filter.slope() * 1.0e3f;
@@ -528,12 +524,6 @@ void AP_Baro::init(void)
         sensors[i].bus_id.set(0);
     }
 
-    if (_hil_mode) {
-        drivers[0] = new AP_Baro_HIL(*this);
-        _num_drivers = 1;
-        return;
-    }
-
 #if HAL_ENABLE_LIBUAVCAN_DRIVERS
     // Detect UAVCAN Modules, try as many times as there are driver slots
     for (uint8_t i = 0; i < BARO_MAX_DRIVERS; i++) {
@@ -636,9 +626,6 @@ void AP_Baro::init(void)
     for(uint8_t i = 0; i < sitl->baro_count; i++) {
         ADD_BACKEND(new AP_Baro_SITL(*this));
     }
-#elif HAL_BARO_DEFAULT == HAL_BARO_HIL
-    drivers[0] = new AP_Baro_HIL(*this);
-    _num_drivers = 1;
 #elif HAL_BARO_DEFAULT == HAL_BARO_LPS25H_IMU_I2C
 	ADD_BACKEND(AP_Baro_LPS2XH::probe_InvensenseIMU(*this,
                                                     std::move(GET_I2C_DEVICE(HAL_BARO_LPS25H_I2C_BUS, HAL_BARO_LPS25H_I2C_ADDR)),
@@ -837,10 +824,8 @@ void AP_Baro::update(void)
         _alt_offset_active = _alt_offset;
     }
 
-    if (!_hil_mode) {
-        for (uint8_t i=0; i<_num_drivers; i++) {
-            drivers[i]->backend_update(i);
-        }
+    for (uint8_t i=0; i<_num_drivers; i++) {
+        drivers[i]->backend_update(i);
     }
 
     for (uint8_t i=0; i<_num_sensors; i++) {
@@ -868,12 +853,6 @@ void AP_Baro::update(void)
                 sensors[i].altitude = altitude + _alt_offset_active;
             }
         }
-        if (_hil.have_alt) {
-            sensors[0].altitude = _hil.altitude;
-        }
-        if (_hil.have_last_update) {
-            sensors[0].last_update_ms = _hil.last_update_ms;
-        }
     }
 
     // ensure the climb rate filter is updated
diff --git a/libraries/AP_Baro/AP_Baro.h b/libraries/AP_Baro/AP_Baro.h
index fcaa9edd85..1973d827ec 100644
--- a/libraries/AP_Baro/AP_Baro.h
+++ b/libraries/AP_Baro/AP_Baro.h
@@ -145,13 +145,6 @@ public:
     float get_external_temperature(void) const { return get_external_temperature(_primary); };
     float get_external_temperature(const uint8_t instance) const;
 
-    // HIL (and SITL) interface, setting altitude
-    void setHIL(float altitude_msl);
-
-    // HIL (and SITL) interface, setting pressure, temperature, altitude and climb_rate
-    // used by Replay
-    void setHIL(uint8_t instance, float pressure, float temperature, float altitude, float climb_rate, uint32_t last_update_ms);
-
     // Set the primary baro
     void set_primary_baro(uint8_t primary) { _primary_baro.set_and_save(primary); };
 
@@ -161,18 +154,6 @@ public:
     // Get the type (Air or Water) of a particular instance
     baro_type_t get_type(uint8_t instance) { return sensors[instance].type; };
 
-    // HIL variables
-    struct {
-        float pressure;
-        float temperature;
-        float altitude;
-        float climb_rate;
-        uint32_t last_update_ms;
-        bool updated:1;
-        bool have_alt:1;
-        bool have_last_update:1;
-    } _hil;
-
     // register a new sensor, claiming a sensor slot. If we are out of
     // slots it will panic
     uint8_t register_sensor(void);
@@ -180,9 +161,6 @@ public:
     // return number of registered sensors
     uint8_t num_instances(void) const { return _num_sensors; }
 
-    // enable HIL mode
-    void set_hil_mode(void) { _hil_mode = true; }
-
     // set baro drift amount
     void set_baro_drift_altitude(float alt) { _alt_offset = alt; }
 
@@ -298,7 +276,6 @@ private:
     DerivativeFilterFloat_Size7         _climb_rate_filter;
     AP_Float                            _specific_gravity; // the specific gravity of fluid for an ROV 1.00 for freshwater, 1.024 for salt water
     AP_Float                            _user_ground_temperature; // user override of the ground temperature used for EAS2TAS
-    bool                                _hil_mode:1;
     float                               _guessed_ground_temperature; // currently ground temperature estimate using our best abailable source
 
     // when did we last notify the GCS of new pressure reference?
diff --git a/libraries/AP_Baro/AP_Baro_HIL.cpp b/libraries/AP_Baro/AP_Baro_HIL.cpp
index 52de181fb8..7a60f6221b 100644
--- a/libraries/AP_Baro/AP_Baro_HIL.cpp
+++ b/libraries/AP_Baro/AP_Baro_HIL.cpp
@@ -1,15 +1,9 @@
-#include "AP_Baro_HIL.h"
+#include "AP_Baro.h"
 
 #include <AP_HAL/AP_HAL.h>
 
 extern const AP_HAL::HAL& hal;
 
-AP_Baro_HIL::AP_Baro_HIL(AP_Baro &baro) :
-    AP_Baro_Backend(baro)
-{
-    _instance = _frontend.register_sensor();
-}
-
 // ==========================================================================
 // based on tables.cpp from http://www.pdas.com/atmosdownload.html
 
@@ -76,50 +70,3 @@ void AP_Baro::SimpleUnderWaterAtmosphere(
     const float S = seaTempSurface * 0.338f;
     theta = 1.0f / ((1.8e-4f) * S * (alt * 1e3f) + 1.0f);
 }
-
-/*
-  convert an altitude in meters above sea level to a presssure and temperature
- */
-void AP_Baro::setHIL(float altitude_msl)
-{
-    float sigma, delta, theta;
-
-    SimpleAtmosphere(altitude_msl*0.001f, sigma, delta, theta);
-    float p = SSL_AIR_PRESSURE * delta;
-    float T = 303.16f * theta - C_TO_KELVIN; // Assume 30 degrees at sea level - converted to degrees Kelvin
-
-    _hil.pressure = p;
-    _hil.temperature = T;
-    _hil.updated = true;
-}
-
-/*
-  set HIL pressure and temperature for an instance
- */
-void AP_Baro::setHIL(uint8_t instance, float pressure, float temperature, float altitude, float climb_rate, uint32_t last_update_ms)
-{
-    if (instance >= _num_sensors) {
-        // invalid
-        return;
-    }
-    _hil.pressure = pressure;
-    _hil.temperature = temperature;
-    _hil.altitude = altitude;
-    _hil.climb_rate = climb_rate;
-    _hil.updated = true;
-    _hil.have_alt = true;
-
-    if (last_update_ms != 0) {
-        _hil.last_update_ms = last_update_ms;
-        _hil.have_last_update = true;
-    }
-}
-
-// Read the sensor
-void AP_Baro_HIL::update(void)
-{
-    if (_frontend._hil.updated) {
-        _frontend._hil.updated = false;
-        _copy_to_frontend(0, _frontend._hil.pressure, _frontend._hil.temperature);
-    }
-}
diff --git a/libraries/AP_Baro/AP_Baro_HIL.h b/libraries/AP_Baro/AP_Baro_HIL.h
deleted file mode 100644
index 0d0811bc88..0000000000
--- a/libraries/AP_Baro/AP_Baro_HIL.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
-  dummy backend for HIL (and SITL). This doesn't actually need to do
-  any work, as setHIL() is in the frontend
- */
-#pragma once
-
-#include "AP_Baro_Backend.h"
-
-class AP_Baro_HIL : public AP_Baro_Backend
-{
-public:
-    AP_Baro_HIL(AP_Baro &baro);
-    void update(void) override;
-
-private:
-    uint8_t _instance;
-};