diff --git a/src/main/kotlin/roomescape/schedule/business/ScheduleValidator.kt b/src/main/kotlin/roomescape/schedule/business/ScheduleValidator.kt
index 4baf7790..e81739f4 100644
--- a/src/main/kotlin/roomescape/schedule/business/ScheduleValidator.kt
+++ b/src/main/kotlin/roomescape/schedule/business/ScheduleValidator.kt
@@ -33,16 +33,17 @@ class ScheduleValidator(
         val date: LocalDate = schedule.date
         val time: LocalTime = request.time ?: schedule.time
 
-        validateDateTime(date, time)
+        validateNotInPast(date, time)
     }
 
-    fun validateCanCreate(request: ScheduleCreateRequest) {
+    fun validateCanCreate(storeId: Long, request: ScheduleCreateRequest) {
         val date: LocalDate = request.date
         val time: LocalTime = request.time
         val themeId: Long = request.themeId
 
         validateAlreadyExists(date, themeId, time)
-        validateDateTime(date, time)
+        validateNotInPast(date, time)
+        validateTimeNotConflict(storeId, request.date, request.themeId, request.time)
     }
 
     private fun validateAlreadyExists(date: LocalDate, themeId: Long, time: LocalTime) {
@@ -54,7 +55,7 @@ class ScheduleValidator(
         }
     }
 
-    private fun validateDateTime(date: LocalDate, time: LocalTime) {
+    private fun validateNotInPast(date: LocalDate, time: LocalTime) {
         val dateTime = LocalDateTime.of(date, time)
 
         if (dateTime.isBefore(LocalDateTime.now())) {
@@ -64,4 +65,13 @@ class ScheduleValidator(
             throw ScheduleException(ScheduleErrorCode.PAST_DATE_TIME)
         }
     }
+
+    private fun validateTimeNotConflict(storeId: Long, date: LocalDate, themeId: Long, time: LocalTime) {
+        scheduleRepository.findStoreSchedulesWithThemeByDate(storeId, date, themeId)
+            .firstOrNull { it.containsTime(time) }
+            ?.let {
+                log.info { "[ScheduleValidator.validateTimeNotConflict] 시간이 겹치는 일정 존재: conflictSchedule(Id=${it.id}, time=${it.time}~${it.getEndAt()})" }
+                throw ScheduleException(ScheduleErrorCode.SCHEDULE_TIME_CONFLICT)
+            }
+    }
 }
diff --git a/src/main/kotlin/roomescape/schedule/exception/ScheduleErrorCode.kt b/src/main/kotlin/roomescape/schedule/exception/ScheduleErrorCode.kt
index 096fce94..696d6630 100644
--- a/src/main/kotlin/roomescape/schedule/exception/ScheduleErrorCode.kt
+++ b/src/main/kotlin/roomescape/schedule/exception/ScheduleErrorCode.kt
@@ -12,5 +12,6 @@ enum class ScheduleErrorCode(
     SCHEDULE_ALREADY_EXISTS(HttpStatus.CONFLICT, "S002", "이미 동일한 일정이 있어요."),
     PAST_DATE_TIME(HttpStatus.BAD_REQUEST, "S003", "과거 날짜와 시간은 선택할 수 없어요."),
     SCHEDULE_IN_USE(HttpStatus.CONFLICT, "S004", "예약이 진행중이거나 완료된 일정은 삭제할 수 없어요."),
-    SCHEDULE_NOT_AVAILABLE(HttpStatus.CONFLICT, "S005", "예약이 완료되었거나 예약할 수 없는 일정이에요.")
+    SCHEDULE_NOT_AVAILABLE(HttpStatus.CONFLICT, "S005", "예약이 완료되었거나 예약할 수 없는 일정이에요."),
+    SCHEDULE_TIME_CONFLICT(HttpStatus.CONFLICT, "S006", "시간이 겹치는 다른 일정이 있어요.")
 }