diff --git a/src/main/java/com/petlog/diary/controller/DiaryController.java b/src/main/java/com/petlog/diary/controller/DiaryController.java
index b7eab4c..37b52c1 100644
--- a/src/main/java/com/petlog/diary/controller/DiaryController.java
+++ b/src/main/java/com/petlog/diary/controller/DiaryController.java
@@ -8,6 +8,7 @@
 import com.petlog.diary.controller.dto.response.GetDiaryResponseDto;
 import com.petlog.diary.service.DiaryService;
 import com.petlog.diary.service.dto.CreateDiaryDto;
+import com.petlog.diary.service.dto.GetDiaryDto;
 import com.petlog.diary.service.dto.GetDiaryInfoDto;
 import com.petlog.docs.DiaryControllerDocs;
 import lombok.RequiredArgsConstructor;
@@ -21,7 +22,6 @@
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
-import java.time.LocalDate;
 import java.util.List;
 
 import static com.petlog.diary.controller.DiarySuccessCode.CREATE_DIARY;
@@ -71,10 +71,18 @@ public ResponseEntity<ApiResponse<GetAllDiaryResponseDto>> getAllDiary(
 
     @GetMapping("/{diaryId}")
     public ResponseEntity<ApiResponse<GetDiaryResponseDto>> getDiary(
+        @Authenticated final Long memberId,
         @PathVariable final Long groupId,
         @PathVariable final Long diaryId
     ) {
-        final GetDiaryResponseDto response = new GetDiaryResponseDto("제목", "내용", List.of("이미지"), LocalDate.now(), "서은");
+        final GetDiaryDto dto = diaryService.getDiary(memberId, groupId, diaryId);
+        final GetDiaryResponseDto response = new GetDiaryResponseDto(
+            dto.title(),
+            dto.content(),
+            dto.images(),
+            dto.writtenAt(),
+            dto.writerName()
+        );
 
         return ResponseEntity.ok(
             ApiResponse.successWithData(GET_DIARY, response)
diff --git a/src/main/java/com/petlog/diary/controller/dto/response/GetDiaryResponseDto.java b/src/main/java/com/petlog/diary/controller/dto/response/GetDiaryResponseDto.java
index 994198f..4715a62 100644
--- a/src/main/java/com/petlog/diary/controller/dto/response/GetDiaryResponseDto.java
+++ b/src/main/java/com/petlog/diary/controller/dto/response/GetDiaryResponseDto.java
@@ -1,6 +1,8 @@
 package com.petlog.diary.controller.dto.response;
 
+import com.fasterxml.jackson.annotation.JsonFormat;
 import io.swagger.v3.oas.annotations.media.Schema;
+import org.springframework.format.annotation.DateTimeFormat;
 
 import java.time.LocalDate;
 import java.util.List;
@@ -16,22 +18,11 @@ public record GetDiaryResponseDto(
     @Schema(description = "0~6장")
     List<String> images,
 
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy.MM.dd")
+    @DateTimeFormat(pattern = "yyyy.MM.dd")
     LocalDate writtenAt,
 
     String writerName
 
 ) {
-    public GetDiaryResponseDto(
-        final String title,
-        final String content,
-        final List<String> images,
-        final LocalDate writtenAt,
-        final String writerName
-    ) {
-        this.title = title;
-        this.content = content;
-        this.images = images;
-        this.writtenAt = writtenAt;
-        this.writerName = writerName;
-    }
 }
diff --git a/src/main/java/com/petlog/diary/service/DiaryService.java b/src/main/java/com/petlog/diary/service/DiaryService.java
index f7136ec..6332ec6 100644
--- a/src/main/java/com/petlog/diary/service/DiaryService.java
+++ b/src/main/java/com/petlog/diary/service/DiaryService.java
@@ -5,6 +5,7 @@
 import com.petlog.diary.repository.DiaryImageRepository;
 import com.petlog.diary.repository.DiaryRepository;
 import com.petlog.diary.service.dto.CreateDiaryDto;
+import com.petlog.diary.service.dto.GetDiaryDto;
 import com.petlog.diary.service.dto.GetDiaryInfoDto;
 import com.petlog.member.entity.Member;
 import com.petlog.member.repository.MemberRepository;
@@ -64,6 +65,7 @@ private PetGroupMember getPetGroupMember(final Member member, final PetGroup pet
             .orElseThrow(() -> new IllegalArgumentException("그룹에 존재하지 않는 회원입니다."));
     }
 
+    @Transactional(readOnly = true)
     public List<GetDiaryInfoDto> getAllDiaries(final Long memberId, final Long groupId) {
         final Member member = getMember(memberId);
         final PetGroup petGroup = getPetGroup(groupId);
@@ -83,4 +85,27 @@ public List<GetDiaryInfoDto> getAllDiaries(final Long memberId, final Long group
             ))
             .toList();
     }
+
+    public GetDiaryDto getDiary(final Long memberId, final Long groupId, final Long diaryId) {
+        final Member member = getMember(memberId);
+        final PetGroup petGroup = getPetGroup(groupId);
+        getPetGroupMember(member, petGroup);
+
+        final Diary diary = getDiaryDetail(diaryId);
+
+        return new GetDiaryDto(
+            diary.getTitle(),
+            diary.getContent(),
+            diary.getImages().stream()
+                    .map(DiaryImage::getImageUrl)
+                    .toList(),
+            diary.getWrittenAt(),
+            diary.getMember().getName()
+        );
+    }
+
+    private Diary getDiaryDetail(final Long diaryId) {
+        return diaryRepository.findById(diaryId)
+            .orElseThrow(() -> new IllegalArgumentException("존재하지 않는 일기입니다."));
+    }
 }
diff --git a/src/main/java/com/petlog/diary/service/dto/GetDailyDiaryDto.java b/src/main/java/com/petlog/diary/service/dto/GetDailyDiaryDto.java
index 6528593..0eb9775 100644
--- a/src/main/java/com/petlog/diary/service/dto/GetDailyDiaryDto.java
+++ b/src/main/java/com/petlog/diary/service/dto/GetDailyDiaryDto.java
@@ -1,19 +1,17 @@
 package com.petlog.diary.service.dto;
 
+import com.fasterxml.jackson.annotation.JsonFormat;
+import org.springframework.format.annotation.DateTimeFormat;
+
 import java.time.LocalDate;
 import java.util.List;
 
 public record GetDailyDiaryDto(
 
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy.MM.dd")
+    @DateTimeFormat(pattern = "yyyy.MM.dd")
     LocalDate writtenAt,
     List<GetDiaryInfoDto> diaryInfo
 
 ) {
-    public GetDailyDiaryDto(
-        final LocalDate writtenAt,
-        final List<GetDiaryInfoDto> diaryInfo
-    ) {
-        this.writtenAt = writtenAt;
-        this.diaryInfo = diaryInfo;
-    }
 }
diff --git a/src/main/java/com/petlog/diary/service/dto/GetDiaryDto.java b/src/main/java/com/petlog/diary/service/dto/GetDiaryDto.java
new file mode 100644
index 0000000..f681e86
--- /dev/null
+++ b/src/main/java/com/petlog/diary/service/dto/GetDiaryDto.java
@@ -0,0 +1,15 @@
+package com.petlog.diary.service.dto;
+
+import java.time.LocalDate;
+import java.util.List;
+
+public record GetDiaryDto(
+
+    String title,
+    String content,
+    List<String> images,
+    LocalDate writtenAt,
+    String writerName
+
+) {
+}
diff --git a/src/main/java/com/petlog/diary/service/dto/GetDiaryInfoDto.java b/src/main/java/com/petlog/diary/service/dto/GetDiaryInfoDto.java
index 0e9501a..e57d721 100644
--- a/src/main/java/com/petlog/diary/service/dto/GetDiaryInfoDto.java
+++ b/src/main/java/com/petlog/diary/service/dto/GetDiaryInfoDto.java
@@ -1,5 +1,6 @@
 package com.petlog.diary.service.dto;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import io.swagger.v3.oas.annotations.media.Schema;
 
 import java.time.LocalDate;
@@ -13,6 +14,7 @@ public record GetDiaryInfoDto(
 
     String image,
 
+    @JsonIgnore
     LocalDate writtenAt
 
 ) {
diff --git a/src/main/java/com/petlog/docs/DiaryControllerDocs.java b/src/main/java/com/petlog/docs/DiaryControllerDocs.java
index a1c21f2..70309ca 100644
--- a/src/main/java/com/petlog/docs/DiaryControllerDocs.java
+++ b/src/main/java/com/petlog/docs/DiaryControllerDocs.java
@@ -25,7 +25,7 @@ public interface DiaryControllerDocs {
 
     @io.swagger.v3.oas.annotations.responses.ApiResponse(responseCode = "200", description = "일기 상세 조회에 성공하였습니다.")
     @Operation(summary = "일기 상세 조회 API")
-    ResponseEntity<ApiResponse<GetDiaryResponseDto>> getDiary(@PathVariable final Long groupId, @PathVariable final Long diaryId);
+    ResponseEntity<ApiResponse<GetDiaryResponseDto>> getDiary(@Authenticated final Long memberId, @PathVariable final Long groupId, @PathVariable final Long diaryId);
 
     @io.swagger.v3.oas.annotations.responses.ApiResponse(responseCode = "200", description = "일기 상세 내용 수정에 성공하였습니다.")
     @Operation(summary = "일기 상세 내용 수정 API")