diff --git a/A00_Common/spreadsheet/spreadsheet_menu.ts b/A00_Common/spreadsheet/spreadsheet_menu.ts
index f2b7f2ee..cc4d585b 100644
--- a/A00_Common/spreadsheet/spreadsheet_menu.ts
+++ b/A00_Common/spreadsheet/spreadsheet_menu.ts
@@ -1,16 +1,20 @@
 /* =============================================================================
  * spreadsheet_menu.ts  (주인 E)
  * 우클릭 메뉴 — 칸 · 행 머리 · 열 머리마다: 잘라내기 · 복사 · (붙여넣기 = 「Ctrl+V 를 쓸 것」 안내) ·
- * 행열 넣기 · 지우기 · 숨기기 · 보이기 · 내용 지우기 · 서식 지우기 · 병합 · 풀기.
+ * 행열 넣기 · 지우기 · 숨기기 · 보이기 · 내용 지우기 · 서식 지우기 · 병합 · 풀기 · 메모 삽입/편집/삭제.
  * `ui_template_context_menu.ts` 재사용 — 우클릭 밖 자리는 그냥 눌러 선택부터 옮김.
+ * 메모는 `spreadsheet_comments.ts`(sub1 · 브레인 답 2026-09-27)의 `setComment` · `deleteComment` ·
+ * `getComment` 를 부름 — 안에서 「시트통째」 명령 · 되돌리기 짝까지 만듦. 글 입력 창은 이 파일이
+ * 직접 띄움(작은 오버레이 · `showConfirmDialog` 와 같은 결의 자체 모달 · native prompt 안 씀).
  *
  * 이음(D `spreadsheet.ts` 잇는 자리) — `attachMenu(ctx)` 한 번 부름(반환 `root` = 메뉴 껍데기 ·
  * 안 붙여도 됨 · `ctx.root` 안에 스스로 넣음). `ctx.grid.hitTest` 가 준비된 뒤(C 격자 붙은 뒤) 불러야 함.
  * ========================================================================== */
 
 import { createMapContextMenu, type MapContextMenuItem } from "@ui/ui_template_context_menu";
-import { showToast } from "@ui/ui_template_elements";
+import { createButton, el, showToast } from "@ui/ui_template_elements";
 import { rangeToA1 } from "./spreadsheet_address";
+import { deleteComment, getComment, setComment } from "./spreadsheet_comments";
 import { st } from "./spreadsheet_text";
 import { MAX_COLS, MAX_ROWS, type CellRange } from "./spreadsheet_types";
 import type { PartHandle, SpreadsheetContext } from "./spreadsheet_view_types";
@@ -36,7 +40,39 @@ export function attachMenu(ctx: SpreadsheetContext): PartHandle {
     document.execCommand(kind);
   }
 
-  function cellMenuItems(range: CellRange): MapContextMenuItem[] {
+  /** 메모 글 입력 — 작은 오버레이(native prompt 안 씀, 자동화 창이 native 창을 자동 취소하는
+   * 문제는 `showConfirmDialog` 머리 주석과 같은 까닭). 저장을 누르면 `onSave`. */
+  function openCommentEditor(initial: string, onSave: (text: string) => void): void {
+    const overlay = el("div", { className: "ss-comment-editor" });
+    const panel = el("div", { className: "ss-comment-editor__panel" });
+    const textarea = el("textarea", {
+      className: "ss-comment-editor__input",
+    }) as HTMLTextAreaElement;
+    textarea.value = initial;
+    const done = (): void => overlay.remove();
+    const actions = el("div", {
+      className: "ss-comment-editor__actions",
+      children: [
+        createButton({ label: "취소", variant: "ghost", onClick: done }),
+        createButton({
+          label: "저장",
+          variant: "filled",
+          onClick: () => {
+            onSave(textarea.value);
+            done();
+          },
+        }),
+      ],
+    });
+    panel.append(textarea, actions);
+    overlay.append(panel);
+    document.body.append(overlay);
+    textarea.focus();
+    textarea.select();
+  }
+
+  function cellMenuItems(range: CellRange, r: number, c: number): MapContextMenuItem[] {
+    const note = getComment(ctx.sheet(), r, c);
     return [
       [st("MenuCut"), () => cutCopy("cut")],
       [st("MenuCopy"), () => cutCopy("copy")],
@@ -58,6 +94,13 @@ export function attachMenu(ctx: SpreadsheetContext): PartHandle {
               : { 종류: "병합", 시트: ctx.selection.시트, 범위: range },
           ),
       ],
+      [
+        note ? st("MenuCommentEdit") : st("MenuCommentInsert"),
+        () => openCommentEditor(note ?? "", (text) => setComment(ctx, r, c, text)),
+      ],
+      ...(note
+        ? ([[st("MenuCommentDelete"), () => deleteComment(ctx, r, c)]] as MapContextMenuItem[])
+        : []),
     ];
   }
 
@@ -196,7 +239,7 @@ export function attachMenu(ctx: SpreadsheetContext): PartHandle {
         });
       }
       const active = ctx.selection.범위[0] ?? range(hit.r, hit.c, hit.r, hit.c);
-      menu.open(x, y, cellMenuItems(active));
+      menu.open(x, y, cellMenuItems(active, hit.r, hit.c));
     }
   }
 
diff --git a/A00_Common/spreadsheet/spreadsheet_text.ts b/A00_Common/spreadsheet/spreadsheet_text.ts
index 67546a24..9eb36a89 100644
--- a/A00_Common/spreadsheet/spreadsheet_text.ts
+++ b/A00_Common/spreadsheet/spreadsheet_text.ts
@@ -78,6 +78,9 @@ const TEXT = {
   MenuClearFormat: ["서식 지우기", "Clear format"],
   MenuMerge: ["병합", "Merge"],
   MenuUnmerge: ["병합 해제", "Unmerge"],
+  MenuCommentInsert: ["메모 삽입", "Insert comment"],
+  MenuCommentEdit: ["메모 편집", "Edit comment"],
+  MenuCommentDelete: ["메모 삭제", "Delete comment"],
   ClipboardPasteFailed: ["붙여넣기를 읽지 못함", "Could not read paste content"],
 } as const;
 
diff --git a/A00_Common/spreadsheet/spreadsheet_toolbar.css b/A00_Common/spreadsheet/spreadsheet_toolbar.css
index 864f26b1..d43a375f 100644
--- a/A00_Common/spreadsheet/spreadsheet_toolbar.css
+++ b/A00_Common/spreadsheet/spreadsheet_toolbar.css
@@ -215,3 +215,43 @@
   margin: 2px 4px;
   border-top: 1px solid var(--color-border);
 }
+
+/* ── 메모 편집 창(칸 우클릭 [메모 삽입 · 편집]) ──────────────────────────────── */
+
+.ss-comment-editor {
+  position: fixed;
+  inset: 0;
+  z-index: var(--z-modal);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: rgb(0 0 0 / 35%);
+}
+
+.ss-comment-editor__panel {
+  display: flex;
+  flex-direction: column;
+  gap: var(--spacing-8);
+  width: 280px;
+  padding: var(--spacing-16);
+  border-radius: var(--radius-cards);
+  background: var(--color-surface-raised);
+  box-shadow: var(--shadow-lg);
+}
+
+.ss-comment-editor__input {
+  min-height: 80px;
+  padding: var(--spacing-8);
+  border: 1px solid var(--color-border);
+  border-radius: var(--radius-sm);
+  background: var(--color-canvas);
+  color: var(--color-text-body);
+  font: inherit;
+  resize: vertical;
+}
+
+.ss-comment-editor__actions {
+  display: flex;
+  justify-content: flex-end;
+  gap: var(--spacing-8);
+}