diff --git a/src/main/java/com/petlog/docs/ScheduleControllerDocs.java b/src/main/java/com/petlog/docs/ScheduleControllerDocs.java
index 86de46b..31d0b7b 100644
--- a/src/main/java/com/petlog/docs/ScheduleControllerDocs.java
+++ b/src/main/java/com/petlog/docs/ScheduleControllerDocs.java
@@ -28,7 +28,7 @@ public interface ScheduleControllerDocs {
 
     @io.swagger.v3.oas.annotations.responses.ApiResponse(responseCode = "200", description = "일정 상세 내용 수정에 성공하였습니다.")
     @Operation(summary = "일정 상세 내용 수정 API")
-    ResponseEntity<ApiResponse<Void>> updateSchedule(@PathVariable final Long groupId, @PathVariable final Long scheduleId, @RequestBody final UpdateScheduleRequestDto request);
+    ResponseEntity<ApiResponse<Void>> updateSchedule(@Authenticated final Long memberId, @PathVariable final Long groupId, @PathVariable final Long scheduleId, @RequestBody final UpdateScheduleRequestDto request);
 
     @io.swagger.v3.oas.annotations.responses.ApiResponse(responseCode = "200", description = "일정 삭제에 성공하였습니다.")
     @Operation(summary = "일정 삭제 API")
diff --git a/src/main/java/com/petlog/schedule/controller/ScheduleController.java b/src/main/java/com/petlog/schedule/controller/ScheduleController.java
index aab4422..2c8e5fa 100644
--- a/src/main/java/com/petlog/schedule/controller/ScheduleController.java
+++ b/src/main/java/com/petlog/schedule/controller/ScheduleController.java
@@ -9,6 +9,7 @@
 import com.petlog.schedule.service.ScheduleService;
 import com.petlog.schedule.service.dto.CreateScheduleDto;
 import com.petlog.schedule.service.dto.GetScheduleInfoDto;
+import com.petlog.schedule.service.dto.UpdateScheduleDto;
 import lombok.RequiredArgsConstructor;
 import org.springframework.format.annotation.DateTimeFormat;
 import org.springframework.http.ResponseEntity;
@@ -76,10 +77,22 @@ public ResponseEntity<ApiResponse<GetMonthlyScheduleResponseDto>> getAllSchedule
 
     @PatchMapping("/{scheduleId}")
     public ResponseEntity<ApiResponse<Void>> updateSchedule(
+        @Authenticated final Long memberId,
         @PathVariable final Long groupId,
         @PathVariable final Long scheduleId,
         @RequestBody final UpdateScheduleRequestDto request
     ) {
+        final UpdateScheduleDto dto = new UpdateScheduleDto(
+            request.title(),
+            request.isAllDay(),
+            request.startTime(),
+            request.endTime(),
+            request.remindNotificationAt(),
+            request.tag(),
+            request.memo()
+        );
+        scheduleService.updateSchedule(memberId, groupId, scheduleId, dto);
+
         return ResponseEntity.ok(
             ApiResponse.success(UPDATE_SCHEDULE)
         );
diff --git a/src/main/java/com/petlog/schedule/controller/dto/request/UpdateScheduleRequestDto.java b/src/main/java/com/petlog/schedule/controller/dto/request/UpdateScheduleRequestDto.java
index 8c3918e..2114cef 100644
--- a/src/main/java/com/petlog/schedule/controller/dto/request/UpdateScheduleRequestDto.java
+++ b/src/main/java/com/petlog/schedule/controller/dto/request/UpdateScheduleRequestDto.java
@@ -18,11 +18,11 @@ public record UpdateScheduleRequestDto(
     @Schema(description = "isAllDay가 true면 해당 날짜의 자정 시간으로 보내야함")
     LocalDateTime endTime,
 
+    LocalDateTime remindNotificationAt,
+
     @Schema(description = "YELLOW/GREEN/BLUE")
     ScheduleType tag,
 
-    LocalDateTime remindNotificationAt,
-
     @Schema(description = "300글자 제한")
     String memo
 
diff --git a/src/main/java/com/petlog/schedule/entity/Schedule.java b/src/main/java/com/petlog/schedule/entity/Schedule.java
index 7cab007..c58ae00 100644
--- a/src/main/java/com/petlog/schedule/entity/Schedule.java
+++ b/src/main/java/com/petlog/schedule/entity/Schedule.java
@@ -81,4 +81,22 @@ public Schedule(
         this.type = type;
         this.memo = memo;
     }
+
+    public void update(
+        final String title,
+        final boolean isAllDay,
+        final LocalDateTime startTime,
+        final LocalDateTime endTime,
+        final LocalDateTime remindNotificationAt,
+        final ScheduleType tag,
+        final String memo
+    ) {
+        this.title = title;
+        this.isAllDay = isAllDay;
+        this.startAt = startTime;
+        this.endAt = endTime;
+        this.remindAt = remindNotificationAt;
+        this.type = tag;
+        this.memo = memo;
+    }
 }
diff --git a/src/main/java/com/petlog/schedule/service/ScheduleService.java b/src/main/java/com/petlog/schedule/service/ScheduleService.java
index 4365cd3..b226bac 100644
--- a/src/main/java/com/petlog/schedule/service/ScheduleService.java
+++ b/src/main/java/com/petlog/schedule/service/ScheduleService.java
@@ -10,6 +10,7 @@
 import com.petlog.schedule.repository.ScheduleRepository;
 import com.petlog.schedule.service.dto.CreateScheduleDto;
 import com.petlog.schedule.service.dto.GetScheduleInfoDto;
+import com.petlog.schedule.service.dto.UpdateScheduleDto;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -87,4 +88,35 @@ public List<GetScheduleInfoDto> getMonthlySchedule(final Long memberId, final Lo
             ))
             .toList();
     }
+
+    @Transactional
+    public void updateSchedule(final Long memberId, final Long groupId, final Long scheduleId, final UpdateScheduleDto dto) {
+        final Member member = getMember(memberId);
+        final PetGroup petGroup = getPetGroup(groupId);
+        getPetGroupMember(member, petGroup);
+
+        final Schedule schedule = getSchedule(scheduleId);
+        validateIsScheduleWriter(member, schedule);
+
+        schedule.update(
+            dto.title(),
+            dto.isAllDay(),
+            dto.startTime(),
+            dto.endTime(),
+            dto.remindNotificationAt(),
+            dto.tag(),
+            dto.memo()
+        );
+    }
+
+    private Schedule getSchedule(final Long scheduleId) {
+        return scheduleRepository.findById(scheduleId)
+            .orElseThrow(() -> new IllegalArgumentException("존재하지 않는 일정입니다."));
+    }
+
+    private void validateIsScheduleWriter(final Member member, final Schedule schedule) {
+        if(!schedule.getMember().equals(member)) {
+            throw new IllegalArgumentException("일정 작성자만 수정할 수 있습니다.");
+        }
+    }
 }
diff --git a/src/main/java/com/petlog/schedule/service/dto/UpdateScheduleDto.java b/src/main/java/com/petlog/schedule/service/dto/UpdateScheduleDto.java
new file mode 100644
index 0000000..b81b10e
--- /dev/null
+++ b/src/main/java/com/petlog/schedule/service/dto/UpdateScheduleDto.java
@@ -0,0 +1,18 @@
+package com.petlog.schedule.service.dto;
+
+import com.petlog.schedule.entity.ScheduleType;
+
+import java.time.LocalDateTime;
+
+public record UpdateScheduleDto(
+
+    String title,
+    boolean isAllDay,
+    LocalDateTime startTime,
+    LocalDateTime endTime,
+    LocalDateTime remindNotificationAt,
+    ScheduleType tag,
+    String memo
+
+) {
+}