diff --git a/modules/navigation/SCsub b/modules/navigation/SCsub
index ecc55532cf01..e57b4bd9f363 100644
--- a/modules/navigation/SCsub
+++ b/modules/navigation/SCsub
@@ -11,7 +11,7 @@ env_navigation = env_modules.Clone()
 thirdparty_obj = []
 
 # Recast Thirdparty source files
-if env["builtin_recastnavigation"]:
+if not env["disable_3d"] and env["builtin_recastnavigation"]:
     thirdparty_dir = "#thirdparty/recastnavigation/Recast/"
     thirdparty_sources = [
         "Source/Recast.cpp",
@@ -52,7 +52,7 @@ if env["builtin_rvo2_2d"]:
     env_thirdparty.add_source_files(thirdparty_obj, thirdparty_sources)
 
 # RVO 3D Thirdparty source files
-if env["builtin_rvo2_3d"]:
+if not env["disable_3d"] and env["builtin_rvo2_3d"]:
     thirdparty_dir = "#thirdparty/rvo2/rvo2_3d/"
     thirdparty_sources = [
         "Agent3d.cpp",
diff --git a/modules/navigation/nav_agent.cpp b/modules/navigation/nav_agent.cpp
index 2dbe57eb4aa6..ce4dacd4a120 100644
--- a/modules/navigation/nav_agent.cpp
+++ b/modules/navigation/nav_agent.cpp
@@ -40,12 +40,15 @@ void NavAgent::set_avoidance_enabled(bool p_enabled) {
 	_update_rvo_agent_properties();
 }
 
+#ifndef _3D_DISABLED
 void NavAgent::set_use_3d_avoidance(bool p_enabled) {
 	use_3d_avoidance = p_enabled;
 	_update_rvo_agent_properties();
 }
+#endif
 
 void NavAgent::_update_rvo_agent_properties() {
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.neighborDist_ = neighbor_distance;
 		rvo_agent_3d.maxNeighbors_ = max_neighbors;
@@ -61,7 +64,9 @@ void NavAgent::_update_rvo_agent_properties() {
 		rvo_agent_3d.avoidance_layers_ = avoidance_layers;
 		rvo_agent_3d.avoidance_mask_ = avoidance_mask;
 		rvo_agent_3d.avoidance_priority_ = avoidance_priority;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.neighborDist_ = neighbor_distance;
 		rvo_agent_2d.maxNeighbors_ = max_neighbors;
 		rvo_agent_2d.timeHorizon_ = time_horizon_agents;
@@ -134,9 +139,12 @@ void NavAgent::dispatch_avoidance_callback() {
 
 	Vector3 new_velocity;
 
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		new_velocity = Vector3(rvo_agent_3d.velocity_.x(), rvo_agent_3d.velocity_.y(), rvo_agent_3d.velocity_.z());
-	} else {
+	} else
+#endif
+	{
 		new_velocity = Vector3(rvo_agent_2d.velocity_.x(), 0.0, rvo_agent_2d.velocity_.y());
 	}
 
@@ -150,9 +158,12 @@ void NavAgent::dispatch_avoidance_callback() {
 
 void NavAgent::set_neighbor_distance(real_t p_neighbor_distance) {
 	neighbor_distance = p_neighbor_distance;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.neighborDist_ = neighbor_distance;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.neighborDist_ = neighbor_distance;
 	}
 	agent_dirty = true;
@@ -160,9 +171,12 @@ void NavAgent::set_neighbor_distance(real_t p_neighbor_distance) {
 
 void NavAgent::set_max_neighbors(int p_max_neighbors) {
 	max_neighbors = p_max_neighbors;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.maxNeighbors_ = max_neighbors;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.maxNeighbors_ = max_neighbors;
 	}
 	agent_dirty = true;
@@ -170,9 +184,12 @@ void NavAgent::set_max_neighbors(int p_max_neighbors) {
 
 void NavAgent::set_time_horizon_agents(real_t p_time_horizon) {
 	time_horizon_agents = p_time_horizon;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.timeHorizon_ = time_horizon_agents;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.timeHorizon_ = time_horizon_agents;
 	}
 	agent_dirty = true;
@@ -180,9 +197,12 @@ void NavAgent::set_time_horizon_agents(real_t p_time_horizon) {
 
 void NavAgent::set_time_horizon_obstacles(real_t p_time_horizon) {
 	time_horizon_obstacles = p_time_horizon;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.timeHorizonObst_ = time_horizon_obstacles;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.timeHorizonObst_ = time_horizon_obstacles;
 	}
 	agent_dirty = true;
@@ -190,9 +210,12 @@ void NavAgent::set_time_horizon_obstacles(real_t p_time_horizon) {
 
 void NavAgent::set_radius(real_t p_radius) {
 	radius = p_radius;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.radius_ = radius;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.radius_ = radius;
 	}
 	agent_dirty = true;
@@ -200,9 +223,12 @@ void NavAgent::set_radius(real_t p_radius) {
 
 void NavAgent::set_height(real_t p_height) {
 	height = p_height;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.height_ = height;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.height_ = height;
 	}
 	agent_dirty = true;
@@ -211,9 +237,12 @@ void NavAgent::set_height(real_t p_height) {
 void NavAgent::set_max_speed(real_t p_max_speed) {
 	max_speed = p_max_speed;
 	if (avoidance_enabled) {
+#ifndef _3D_DISABLED
 		if (use_3d_avoidance) {
 			rvo_agent_3d.maxSpeed_ = max_speed;
-		} else {
+		} else
+#endif
+		{
 			rvo_agent_2d.maxSpeed_ = max_speed;
 		}
 	}
@@ -223,9 +252,12 @@ void NavAgent::set_max_speed(real_t p_max_speed) {
 void NavAgent::set_position(const Vector3 p_position) {
 	position = p_position;
 	if (avoidance_enabled) {
+#ifndef _3D_DISABLED
 		if (use_3d_avoidance) {
 			rvo_agent_3d.position_ = RVO3D::Vector3(p_position.x, p_position.y, p_position.z);
-		} else {
+		} else
+#endif
+		{
 			rvo_agent_2d.elevation_ = p_position.y;
 			rvo_agent_2d.position_ = RVO2D::Vector2(p_position.x, p_position.z);
 		}
@@ -242,9 +274,12 @@ void NavAgent::set_velocity(const Vector3 p_velocity) {
 	// This velocity is not guaranteed, RVO simulation will only try to fulfill it
 	velocity = p_velocity;
 	if (avoidance_enabled) {
+#ifndef _3D_DISABLED
 		if (use_3d_avoidance) {
 			rvo_agent_3d.prefVelocity_ = RVO3D::Vector3(velocity.x, velocity.y, velocity.z);
-		} else {
+		} else
+#endif
+		{
 			rvo_agent_2d.prefVelocity_ = RVO2D::Vector2(velocity.x, velocity.z);
 		}
 	}
@@ -258,9 +293,12 @@ void NavAgent::set_velocity_forced(const Vector3 p_velocity) {
 	// use velocity instead to update with a safer "suggestion"
 	velocity_forced = p_velocity;
 	if (avoidance_enabled) {
+#ifndef _3D_DISABLED
 		if (use_3d_avoidance) {
 			rvo_agent_3d.velocity_ = RVO3D::Vector3(p_velocity.x, p_velocity.y, p_velocity.z);
-		} else {
+		} else
+#endif
+		{
 			rvo_agent_2d.velocity_ = RVO2D::Vector2(p_velocity.x, p_velocity.z);
 		}
 	}
@@ -270,9 +308,12 @@ void NavAgent::set_velocity_forced(const Vector3 p_velocity) {
 void NavAgent::update() {
 	// Updates this agent with the calculated results from the rvo simulation
 	if (avoidance_enabled) {
+#ifndef _3D_DISABLED
 		if (use_3d_avoidance) {
 			velocity = Vector3(rvo_agent_3d.velocity_.x(), rvo_agent_3d.velocity_.y(), rvo_agent_3d.velocity_.z());
-		} else {
+		} else
+#endif
+		{
 			velocity = Vector3(rvo_agent_2d.velocity_.x(), 0.0, rvo_agent_2d.velocity_.y());
 		}
 	}
@@ -280,9 +321,12 @@ void NavAgent::update() {
 
 void NavAgent::set_avoidance_mask(uint32_t p_mask) {
 	avoidance_mask = p_mask;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.avoidance_mask_ = avoidance_mask;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.avoidance_mask_ = avoidance_mask;
 	}
 	agent_dirty = true;
@@ -290,9 +334,12 @@ void NavAgent::set_avoidance_mask(uint32_t p_mask) {
 
 void NavAgent::set_avoidance_layers(uint32_t p_layers) {
 	avoidance_layers = p_layers;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.avoidance_layers_ = avoidance_layers;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.avoidance_layers_ = avoidance_layers;
 	}
 	agent_dirty = true;
@@ -302,9 +349,12 @@ void NavAgent::set_avoidance_priority(real_t p_priority) {
 	ERR_FAIL_COND_MSG(p_priority < 0.0, "Avoidance priority must be between 0.0 and 1.0 inclusive.");
 	ERR_FAIL_COND_MSG(p_priority > 1.0, "Avoidance priority must be between 0.0 and 1.0 inclusive.");
 	avoidance_priority = p_priority;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		rvo_agent_3d.avoidance_priority_ = avoidance_priority;
-	} else {
+	} else
+#endif
+	{
 		rvo_agent_2d.avoidance_priority_ = avoidance_priority;
 	}
 	agent_dirty = true;
@@ -319,6 +369,7 @@ bool NavAgent::check_dirty() {
 const Dictionary NavAgent::get_avoidance_data() const {
 	// Returns debug data from RVO simulation internals of this agent.
 	Dictionary _avoidance_data;
+#ifndef _3D_DISABLED
 	if (use_3d_avoidance) {
 		_avoidance_data["max_neighbors"] = int(rvo_agent_3d.maxNeighbors_);
 		_avoidance_data["max_speed"] = float(rvo_agent_3d.maxSpeed_);
@@ -334,7 +385,9 @@ const Dictionary NavAgent::get_avoidance_data() const {
 		_avoidance_data["avoidance_layers"] = int(rvo_agent_3d.avoidance_layers_);
 		_avoidance_data["avoidance_mask"] = int(rvo_agent_3d.avoidance_mask_);
 		_avoidance_data["avoidance_priority"] = float(rvo_agent_3d.avoidance_priority_);
-	} else {
+	} else
+#endif
+	{
 		_avoidance_data["max_neighbors"] = int(rvo_agent_2d.maxNeighbors_);
 		_avoidance_data["max_speed"] = float(rvo_agent_2d.maxSpeed_);
 		_avoidance_data["neighbor_distance"] = float(rvo_agent_2d.neighborDist_);
diff --git a/modules/navigation/nav_agent.h b/modules/navigation/nav_agent.h
index 18997803f25e..3e4dc0249020 100644
--- a/modules/navigation/nav_agent.h
+++ b/modules/navigation/nav_agent.h
@@ -37,7 +37,9 @@
 #include "core/templates/local_vector.h"
 
 #include <Agent2d.h>
+#ifndef _3D_DISABLED
 #include <Agent3d.h>
+#endif
 
 class NavMap;
 
@@ -59,8 +61,10 @@ class NavAgent : public NavRid {
 	NavMap *map = nullptr;
 
 	RVO2D::Agent2D rvo_agent_2d;
+#ifndef _3D_DISABLED
 	RVO3D::Agent3D rvo_agent_3d;
 	bool use_3d_avoidance = false;
+#endif
 	bool avoidance_enabled = false;
 
 	uint32_t avoidance_layers = 1;
@@ -80,8 +84,13 @@ class NavAgent : public NavRid {
 	void set_avoidance_enabled(bool p_enabled);
 	bool is_avoidance_enabled() { return avoidance_enabled; }
 
+#ifdef _3D_DISABLED
+	void set_use_3d_avoidance(bool p_enabled) {}
+	bool get_use_3d_avoidance() { return false; }
+#else
 	void set_use_3d_avoidance(bool p_enabled);
 	bool get_use_3d_avoidance() { return use_3d_avoidance; }
+#endif
 
 	void set_map(NavMap *p_map);
 	NavMap *get_map() { return map; }
@@ -89,7 +98,9 @@ class NavAgent : public NavRid {
 	bool is_map_changed();
 
 	RVO2D::Agent2D *get_rvo_agent_2d() { return &rvo_agent_2d; }
+#ifndef _3D_DISABLED
 	RVO3D::Agent3D *get_rvo_agent_3d() { return &rvo_agent_3d; }
+#endif
 
 	void set_avoidance_callback(Callable p_callback);
 	bool has_avoidance_callback() const;
diff --git a/modules/navigation/nav_map.cpp b/modules/navigation/nav_map.cpp
index 8df1db533d94..4007c7b35f0e 100644
--- a/modules/navigation/nav_map.cpp
+++ b/modules/navigation/nav_map.cpp
@@ -259,13 +259,16 @@ void NavMap::set_agent_as_controlled(NavAgent *agent) {
 		return;
 	}
 
+#ifndef _3D_DISABLED
 	if (agent->get_use_3d_avoidance()) {
 		int64_t agent_3d_index = active_3d_avoidance_agents.find(agent);
 		if (agent_3d_index < 0) {
 			active_3d_avoidance_agents.push_back(agent);
 			agents_dirty = true;
 		}
-	} else {
+	} else
+#endif
+	{
 		int64_t agent_2d_index = active_2d_avoidance_agents.find(agent);
 		if (agent_2d_index < 0) {
 			active_2d_avoidance_agents.push_back(agent);
@@ -275,11 +278,13 @@ void NavMap::set_agent_as_controlled(NavAgent *agent) {
 }
 
 void NavMap::remove_agent_as_controlled(NavAgent *agent) {
+#ifndef _3D_DISABLED
 	int64_t agent_3d_index = active_3d_avoidance_agents.find(agent);
 	if (agent_3d_index >= 0) {
 		active_3d_avoidance_agents.remove_at_unordered(agent_3d_index);
 		agents_dirty = true;
 	}
+#endif
 	int64_t agent_2d_index = active_2d_avoidance_agents.find(agent);
 	if (agent_2d_index >= 0) {
 		active_2d_avoidance_agents.remove_at_unordered(agent_2d_index);
@@ -774,6 +779,7 @@ void NavMap::_update_rvo_agents_tree_2d() {
 	rvo_simulation_2d.kdTree_->buildAgentTree(raw_agents);
 }
 
+#ifndef _3D_DISABLED
 void NavMap::_update_rvo_agents_tree_3d() {
 	// Cannot use LocalVector here as RVO library expects std::vector to build KdTree.
 	std::vector<RVO3D::Agent3D *> raw_agents;
@@ -783,6 +789,7 @@ void NavMap::_update_rvo_agents_tree_3d() {
 	}
 	rvo_simulation_3d.kdTree_->buildAgentTree(raw_agents);
 }
+#endif
 
 void NavMap::_update_rvo_simulation() {
 	if (obstacles_dirty) {
@@ -801,18 +808,22 @@ void NavMap::compute_single_avoidance_step_2d(uint32_t index, NavAgent **agent)
 	(*(agent + index))->update();
 }
 
+#ifndef _3D_DISABLED
 void NavMap::compute_single_avoidance_step_3d(uint32_t index, NavAgent **agent) {
 	(*(agent + index))->get_rvo_agent_3d()->computeNeighbors(&rvo_simulation_3d);
 	(*(agent + index))->get_rvo_agent_3d()->computeNewVelocity(&rvo_simulation_3d);
 	(*(agent + index))->get_rvo_agent_3d()->update(&rvo_simulation_3d);
 	(*(agent + index))->update();
 }
+#endif
 
 void NavMap::step(real_t p_deltatime) {
 	deltatime = p_deltatime;
 
 	rvo_simulation_2d.setTimeStep(float(deltatime));
+#ifndef _3D_DISABLED
 	rvo_simulation_3d.setTimeStep(float(deltatime));
+#endif
 
 	if (active_2d_avoidance_agents.size() > 0) {
 		if (use_threads && avoidance_use_multiple_threads) {
@@ -828,6 +839,7 @@ void NavMap::step(real_t p_deltatime) {
 		}
 	}
 
+#ifndef _3D_DISABLED
 	if (active_3d_avoidance_agents.size() > 0) {
 		if (use_threads && avoidance_use_multiple_threads) {
 			WorkerThreadPool::GroupID group_task = WorkerThreadPool::get_singleton()->add_template_group_task(this, &NavMap::compute_single_avoidance_step_3d, active_3d_avoidance_agents.ptr(), active_3d_avoidance_agents.size(), -1, true, SNAME("RVOAvoidanceAgents3D"));
@@ -841,6 +853,7 @@ void NavMap::step(real_t p_deltatime) {
 			}
 		}
 	}
+#endif
 }
 
 void NavMap::dispatch_callbacks() {
@@ -848,9 +861,11 @@ void NavMap::dispatch_callbacks() {
 		agent->dispatch_avoidance_callback();
 	}
 
+#ifndef _3D_DISABLED
 	for (NavAgent *agent : active_3d_avoidance_agents) {
 		agent->dispatch_avoidance_callback();
 	}
+#endif
 }
 
 void NavMap::_update_merge_rasterizer_cell_dimensions() {
diff --git a/modules/navigation/nav_map.h b/modules/navigation/nav_map.h
index b9120c04d9a0..158564166cc9 100644
--- a/modules/navigation/nav_map.h
+++ b/modules/navigation/nav_map.h
@@ -39,9 +39,11 @@
 #include "servers/navigation/navigation_globals.h"
 
 #include <KdTree2d.h>
-#include <KdTree3d.h>
 #include <RVOSimulator2d.h>
+#ifndef _3D_DISABLED
+#include <KdTree3d.h>
 #include <RVOSimulator3d.h>
+#endif
 
 class NavLink;
 class NavRegion;
@@ -87,11 +89,15 @@ class NavMap : public NavRid {
 
 	/// RVO avoidance worlds
 	RVO2D::RVOSimulator2D rvo_simulation_2d;
+#ifndef _3D_DISABLED
 	RVO3D::RVOSimulator3D rvo_simulation_3d;
+#endif
 
 	/// avoidance controlled agents
 	LocalVector<NavAgent *> active_2d_avoidance_agents;
+#ifndef _3D_DISABLED
 	LocalVector<NavAgent *> active_3d_avoidance_agents;
+#endif
 
 	/// dirty flag when one of the agent's arrays are modified
 	bool agents_dirty = true;
@@ -230,12 +236,20 @@ class NavMap : public NavRid {
 	void compute_single_step(uint32_t index, NavAgent **agent);
 
 	void compute_single_avoidance_step_2d(uint32_t index, NavAgent **agent);
+#ifdef _3D_DISABLED
+	void compute_single_avoidance_step_3d(uint32_t index, NavAgent **agent) {}
+#else
 	void compute_single_avoidance_step_3d(uint32_t index, NavAgent **agent);
+#endif
 
 	void _update_rvo_simulation();
 	void _update_rvo_obstacles_tree_2d();
 	void _update_rvo_agents_tree_2d();
+#ifdef _3D_DISABLED
+	void _update_rvo_agents_tree_3d() {}
+#else
 	void _update_rvo_agents_tree_3d();
+#endif
 
 	void _update_merge_rasterizer_cell_dimensions();
 };
diff --git a/modules/navigation/nav_obstacle.cpp b/modules/navigation/nav_obstacle.cpp
index 14dfd4eae341..f36260f2fc66 100644
--- a/modules/navigation/nav_obstacle.cpp
+++ b/modules/navigation/nav_obstacle.cpp
@@ -58,6 +58,7 @@ void NavObstacle::set_avoidance_enabled(bool p_enabled) {
 	internal_update_agent();
 }
 
+#ifndef _3D_DISABLED
 void NavObstacle::set_use_3d_avoidance(bool p_enabled) {
 	if (use_3d_avoidance == p_enabled) {
 		return;
@@ -70,6 +71,7 @@ void NavObstacle::set_use_3d_avoidance(bool p_enabled) {
 		agent->set_use_3d_avoidance(use_3d_avoidance);
 	}
 }
+#endif
 
 void NavObstacle::set_map(NavMap *p_map) {
 	if (map == p_map) {
@@ -192,7 +194,9 @@ void NavObstacle::internal_update_agent() {
 		agent->set_position(position);
 		agent->set_avoidance_layers(avoidance_layers);
 		agent->set_avoidance_enabled(avoidance_enabled);
+#ifndef _3D_DISABLED
 		agent->set_use_3d_avoidance(use_3d_avoidance);
+#endif
 	}
 }
 
diff --git a/modules/navigation/nav_obstacle.h b/modules/navigation/nav_obstacle.h
index e231e83836c9..f1e12e68efaa 100644
--- a/modules/navigation/nav_obstacle.h
+++ b/modules/navigation/nav_obstacle.h
@@ -50,7 +50,9 @@ class NavObstacle : public NavRid {
 	real_t height = 0.0;
 
 	bool avoidance_enabled = false;
+#ifndef _3D_DISABLED
 	bool use_3d_avoidance = false;
+#endif
 	uint32_t avoidance_layers = 1;
 
 	bool obstacle_dirty = true;
@@ -65,8 +67,13 @@ class NavObstacle : public NavRid {
 	void set_avoidance_enabled(bool p_enabled);
 	bool is_avoidance_enabled() { return avoidance_enabled; }
 
+#ifdef _3D_DISABLED
+	void set_use_3d_avoidance(bool p_enabled) {}
+	bool get_use_3d_avoidance() { return false; }
+#else
 	void set_use_3d_avoidance(bool p_enabled);
 	bool get_use_3d_avoidance() { return use_3d_avoidance; }
+#endif
 
 	void set_map(NavMap *p_map);
 	NavMap *get_map() { return map; }