diff --git a/doorip-api/src/main/java/org/doorip/common/Constants.java b/doorip-api/src/main/java/org/doorip/common/Constants.java
index 3123a06..59e6e74 100644
--- a/doorip-api/src/main/java/org/doorip/common/Constants.java
+++ b/doorip-api/src/main/java/org/doorip/common/Constants.java
@@ -17,4 +17,5 @@ public abstract class Constants {
     public static final int MAX_STYLE_RATE = 100;
     public static final int PROPENSITY_WEIGHT = 25;
     public static final int MAX_PARTICIPANT_COUNT = 6;
+    public static final int MIN_PARTICIPANT_COUNT = 1;
 }
diff --git a/doorip-api/src/main/java/org/doorip/trip/api/TripApiController.java b/doorip-api/src/main/java/org/doorip/trip/api/TripApiController.java
index d748301..3be0d49 100644
--- a/doorip-api/src/main/java/org/doorip/trip/api/TripApiController.java
+++ b/doorip-api/src/main/java/org/doorip/trip/api/TripApiController.java
@@ -2,8 +2,8 @@
 
 import lombok.RequiredArgsConstructor;
 import org.doorip.auth.UserId;
-import org.doorip.common.BaseResponse;
 import org.doorip.common.ApiResponseUtil;
+import org.doorip.common.BaseResponse;
 import org.doorip.message.SuccessMessage;
 import org.doorip.trip.dto.request.TripCreateRequest;
 import org.doorip.trip.dto.request.TripEntryRequest;
@@ -79,10 +79,17 @@ public ResponseEntity<BaseResponse<?>> getParticipants(@UserId final Long userId
         return ApiResponseUtil.success(SuccessMessage.OK, response);
     }
 
+    @PatchMapping("/{tripId}")
+    public ResponseEntity<BaseResponse<?>> leaveTrip(@UserId final Long userId,
+                                                     @PathVariable final Long tripId) {
+        tripDetailService.leaveTrip(userId, tripId);
+        return ApiResponseUtil.success(SuccessMessage.OK);
+    }
+
     @PatchMapping("/{tripId}")
     public ResponseEntity<BaseResponse<?>> updateTrip(@PathVariable final Long tripId,
-                                                     @UserId final Long userId,
-                                                     @RequestBody final TripUpdateRequest request) {
+                                                      @UserId final Long userId,
+                                                      @RequestBody final TripUpdateRequest request) {
         tripService.updateTrip(userId, tripId, request);
         return ApiResponseUtil.success(SuccessMessage.OK);
     }
diff --git a/doorip-api/src/main/java/org/doorip/trip/service/TodoService.java b/doorip-api/src/main/java/org/doorip/trip/service/TodoService.java
index 0a320ae..ce6d4fa 100644
--- a/doorip-api/src/main/java/org/doorip/trip/service/TodoService.java
+++ b/doorip-api/src/main/java/org/doorip/trip/service/TodoService.java
@@ -118,18 +118,18 @@ private Participant getParticipant(Long participantId) {
 
     private List<Todo> getOurTodosAccordingToProgress(Long tripId, String progress) {
         if (progress.equals(Constants.INCOMPLETE)) {
-            return todoRepository.findOurTodoByTripId(tripId, Secret.OUR, Progress.INCOMPLETE);
+            return todoRepository.findOurTodoByTripIdAndSecretAndProgress(tripId, Secret.OUR, Progress.INCOMPLETE);
         } else if (progress.equals(Constants.COMPLETE)) {
-            return todoRepository.findOurTodoByTripId(tripId, Secret.OUR, Progress.COMPLETE);
+            return todoRepository.findOurTodoByTripIdAndSecretAndProgress(tripId, Secret.OUR, Progress.COMPLETE);
         }
         throw new InvalidValueException(ErrorMessage.INVALID_REQUEST_PARAMETER_VALUE);
     }
 
     private List<Todo> getMyTodosAccordingToProgress(Long userId, Long tripId, String progress) {
         if (progress.equals(Constants.INCOMPLETE)) {
-            return todoRepository.findMyTodoByTripId(tripId, userId, Progress.INCOMPLETE);
+            return todoRepository.findMyTodoByTripIdAndUserIdAndProgress(tripId, userId, Progress.INCOMPLETE);
         } else if (progress.equals(Constants.COMPLETE)) {
-            return todoRepository.findMyTodoByTripId(tripId, userId, Progress.COMPLETE);
+            return todoRepository.findMyTodoByTripIdAndUserIdAndProgress(tripId, userId, Progress.COMPLETE);
         }
         throw new InvalidValueException(ErrorMessage.INVALID_REQUEST_PARAMETER_VALUE);
     }
diff --git a/doorip-api/src/main/java/org/doorip/trip/service/TripDetailService.java b/doorip-api/src/main/java/org/doorip/trip/service/TripDetailService.java
index 141f86f..bd0ea67 100644
--- a/doorip-api/src/main/java/org/doorip/trip/service/TripDetailService.java
+++ b/doorip-api/src/main/java/org/doorip/trip/service/TripDetailService.java
@@ -1,19 +1,19 @@
 package org.doorip.trip.service;
 
 import lombok.RequiredArgsConstructor;
+import org.doorip.common.Constants;
 import org.doorip.exception.EntityNotFoundException;
 import org.doorip.message.ErrorMessage;
-import org.doorip.trip.domain.Participant;
-import org.doorip.trip.domain.Progress;
-import org.doorip.trip.domain.Secret;
-import org.doorip.trip.domain.Trip;
+import org.doorip.trip.domain.*;
 import org.doorip.trip.dto.response.MyTodoResponse;
 import org.doorip.trip.dto.response.OurTodoResponse;
 import org.doorip.trip.dto.response.TripParticipantGetResponse;
 import org.doorip.trip.dto.response.TripStyleResponse;
+import org.doorip.trip.repository.ParticipantRepository;
 import org.doorip.trip.repository.TodoRepository;
 import org.doorip.trip.repository.TripRepository;
 import org.doorip.user.domain.User;
+import org.doorip.user.repository.UserRepository;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -28,8 +28,10 @@
 @Transactional(readOnly = true)
 @Service
 public class TripDetailService {
+    private final UserRepository userRepository;
     private final TripRepository tripRepository;
     private final TodoRepository todoRepository;
+    private final ParticipantRepository participantRepository;
 
     public MyTodoResponse getMyTodoDetail(Long userId, Long tripId) {
         Trip findTrip = getTrip(tripId);
@@ -58,6 +60,18 @@ public TripParticipantGetResponse getParticipants(Long userId, Long tripId) {
         return TripParticipantGetResponse.of(participants, response);
     }
 
+    @Transactional
+    public void leaveTrip(Long userId, Long tripId) {
+        User findUser = getUser(userId);
+        Trip findTrip = getTrip(tripId);
+        int size = calculateParticipantsCount(findTrip);
+        Participant findParticipant = getParticipant(findUser, findTrip);
+        List<Todo> todos = todoRepository.findMyTodoByTripIdAndUserIdAndSecret(tripId, userId, Secret.MY);
+        todoRepository.deleteAll(todos);
+        participantRepository.delete(findParticipant);
+        deleteTripIfLastParticipant(size, findTrip);
+    }
+
     private Map<String, Integer> createDefaultPropensity() {
         return new HashMap<>(Map.of(STYLE_A, MIN_STYLE_RATE, STYLE_B, MIN_STYLE_RATE,
                 STYLE_C, MIN_STYLE_RATE, STYLE_D, MIN_STYLE_RATE, STYLE_E, MIN_STYLE_RATE)) {
@@ -105,6 +119,26 @@ private List<TripStyleResponse> calculateAndGetPropensityAverageRates(List<Parti
         return response;
     }
 
+    private User getUser(Long userId) {
+        return userRepository.findById(userId)
+                .orElseThrow(() -> new EntityNotFoundException(ErrorMessage.USER_NOT_FOUND));
+    }
+
+    private int calculateParticipantsCount(Trip findTrip) {
+        return findTrip.getParticipants().size();
+    }
+
+    private Participant getParticipant(User findUser, Trip findTrip) {
+        return participantRepository.findByUserAndTrip(findUser, findTrip)
+                .orElseThrow(() -> new EntityNotFoundException(ErrorMessage.PARTICIPANT_NOT_FOUND));
+    }
+
+    private void deleteTripIfLastParticipant(int size, Trip trip) {
+        if (size == Constants.MIN_PARTICIPANT_COUNT) {
+            tripRepository.delete(trip);
+        }
+    }
+
     private Trip getTrip(Long tripId) {
         return tripRepository.findById(tripId)
                 .orElseThrow(() -> new EntityNotFoundException(ErrorMessage.TRIP_NOT_FOUND));
diff --git a/doorip-domain/src/main/java/org/doorip/trip/repository/ParticipantRepository.java b/doorip-domain/src/main/java/org/doorip/trip/repository/ParticipantRepository.java
index 98df310..b6b857a 100644
--- a/doorip-domain/src/main/java/org/doorip/trip/repository/ParticipantRepository.java
+++ b/doorip-domain/src/main/java/org/doorip/trip/repository/ParticipantRepository.java
@@ -5,6 +5,10 @@
 import org.doorip.user.domain.User;
 import org.springframework.data.jpa.repository.JpaRepository;
 
+import java.util.Optional;
+
 public interface ParticipantRepository extends JpaRepository<Participant, Long> {
     boolean existsByUserAndTrip(User user, Trip trip);
+
+    Optional<Participant> findByUserAndTrip(User user, Trip trip);
 }
diff --git a/doorip-domain/src/main/java/org/doorip/trip/repository/TodoRepository.java b/doorip-domain/src/main/java/org/doorip/trip/repository/TodoRepository.java
index 8d55f8d..dc16927 100644
--- a/doorip-domain/src/main/java/org/doorip/trip/repository/TodoRepository.java
+++ b/doorip-domain/src/main/java/org/doorip/trip/repository/TodoRepository.java
@@ -19,7 +19,20 @@ public interface TodoRepository extends JpaRepository<Todo, Long> {
             "and d.progress = :progress " +
             "and d.secret = :secret " +
             "order by d.endDate")
-    List<Todo> findOurTodoByTripId(@Param("tripId") Long tripId, @Param("secret") Secret secret, @Param("progress") Progress progress);
+    List<Todo> findOurTodoByTripIdAndSecretAndProgress(@Param("tripId") Long tripId, @Param("secret") Secret secret, @Param("progress") Progress progress);
+
+    @Query("select d " +
+            "from Todo d " +
+            "join Trip i " +
+            "on d.trip = i " +
+            "join Participant p " +
+            "on p.trip = i " +
+            "join User u " +
+            "on p.user = u " +
+            "where i.id = :tripId " +
+            "and u.id = :userId " +
+            "and d.secret = :secret")
+    List<Todo> findMyTodoByTripIdAndUserIdAndSecret(@Param("tripId") Long tripId, @Param("userId") Long userId, @Param("secret") Secret secret);
 
     @Query("select d " +
             "from Todo d " +
@@ -35,7 +48,7 @@ public interface TodoRepository extends JpaRepository<Todo, Long> {
             "and u.id = :userId " +
             "and d.progress = :progress " +
             "order by d.endDate")
-    List<Todo> findMyTodoByTripId(@Param("tripId") Long tripId, @Param("userId") Long userId, @Param("progress") Progress progress);
+    List<Todo> findMyTodoByTripIdAndUserIdAndProgress(@Param("tripId") Long tripId, @Param("userId") Long userId, @Param("progress") Progress progress);
 
     int countTodoByTripIdAndSecretAndProgress(Long tripId, Secret secret, Progress progress);