diff --git a/src/plugins/built-in/timetableEdit/index.ts b/src/plugins/built-in/timetableEdit/index.ts
new file mode 100644
index 00000000..0adefb62
--- /dev/null
+++ b/src/plugins/built-in/timetableEdit/index.ts
@@ -0,0 +1,338 @@
+import type { Plugin } from "../../core/types";
+import { waitForElm } from "@/seqta/utils/waitForElm";
+import styles from "./styles.css?inline";
+
+interface TimetableEntryData {
+  ci: number;
+  description: string;
+  room: string;
+  staff: string;
+}
+
+interface TimetableOverrides {
+  [ci: string]: { room?: string; staff?: string };
+}
+
+interface TimetableOverridesBySubject {
+  [description: string]: { room?: string; staff?: string };
+}
+
+interface TimetableStorage {
+  timetableOverrides?: TimetableOverrides;
+  timetableOverridesBySubject?: TimetableOverridesBySubject;
+}
+
+/** SEQTA timetable entries use .teacher and .room as direct children, and data-instance for ci */
+function getRoomAndTeacherElements(entry: HTMLElement): {
+  roomEl: HTMLElement | null;
+  teacherEl: HTMLElement | null;
+} {
+  const roomEl = entry.querySelector(".room") as HTMLElement | null;
+  const teacherEl = entry.querySelector(".teacher") as HTMLElement | null;
+  return { roomEl, teacherEl };
+}
+
+const EDIT_ICON_SVG =
+  '<svg width="24" height="24" viewBox="0 0 24 24"><g style="fill: currentcolor;"><path d="M20.71,7.04C21.1,6.65 21.1,6 20.71,5.63L18.37,3.29C18,2.9 17.35,2.9 16.96,3.29L15.12,5.12L18.87,8.87M3,17.25V21H6.75L17.81,9.93L14.06,6.18L3,17.25Z"/></g></svg>';
+
+function showEditModal(
+  item: TimetableEntryData,
+  overrides: TimetableOverrides | undefined,
+  overridesBySubject: TimetableOverridesBySubject | undefined,
+  onSave: (
+    ci: number,
+    room: string,
+    staff: string,
+    applyToFuture: boolean,
+  ) => void,
+  onClear: (ci: number) => void,
+): void {
+  const overlay = document.createElement("div");
+  overlay.className = "timetable-edit-modal-overlay";
+
+  const modal = document.createElement("div");
+  modal.className = "timetable-edit-modal";
+
+  const override = overrides?.[String(item.ci)] ?? overridesBySubject?.[item.description];
+
+  const roomValue = override?.room ?? item.room ?? "";
+  const staffValue = override?.staff ?? item.staff ?? "";
+
+  const escapeHtml = (s: string) =>
+    s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/"/g, "&quot;");
+  const title = escapeHtml(item.description);
+
+  modal.innerHTML = `
+    <h3>Edit ${title}</h3>
+    <label for="timetable-edit-room">Room</label>
+    <input type="text" id="timetable-edit-room" value="${roomValue.replace(/"/g, "&quot;")}" placeholder="Room" />
+    <label for="timetable-edit-staff">Teacher</label>
+    <input type="text" id="timetable-edit-staff" value="${staffValue.replace(/"/g, "&quot;")}" placeholder="Teacher" />
+    <div class="timetable-edit-modal-checkbox">
+      <input type="checkbox" id="timetable-edit-apply-future" />
+      <label for="timetable-edit-apply-future">Apply to future weeks</label>
+    </div>
+    <div class="timetable-edit-modal-actions">
+      ${override ? '<button type="button" class="timetable-edit-btn-clear">Clear</button>' : ""}
+      <button type="button" class="timetable-edit-btn-cancel">Cancel</button>
+      <button type="button" class="timetable-edit-btn-save">Save</button>
+    </div>
+  `;
+
+  overlay.appendChild(modal);
+
+  const removeModal = () => {
+    overlay.remove();
+    document.removeEventListener("keydown", handleKeydown);
+  };
+
+  const handleKeydown = (e: KeyboardEvent) => {
+    if (e.key === "Escape") removeModal();
+  };
+
+  overlay.addEventListener("click", (e) => {
+    if (e.target === overlay) removeModal();
+  });
+
+  modal.addEventListener("click", (e) => e.stopPropagation());
+  modal.addEventListener("mousedown", (e) => e.stopPropagation());
+  modal.addEventListener("mouseup", (e) => e.stopPropagation());
+
+  const roomInput = modal.querySelector("#timetable-edit-room") as HTMLInputElement;
+  const staffInput = modal.querySelector("#timetable-edit-staff") as HTMLInputElement;
+  const applyFutureCheckbox = modal.querySelector("#timetable-edit-apply-future") as HTMLInputElement;
+
+  modal.querySelector(".timetable-edit-btn-save")?.addEventListener("click", () => {
+    onSave(
+      item.ci,
+      roomInput.value.trim(),
+      staffInput.value.trim(),
+      applyFutureCheckbox?.checked ?? false,
+    );
+    removeModal();
+  });
+
+  modal.querySelector(".timetable-edit-btn-cancel")?.addEventListener("click", removeModal);
+
+  const clearBtn = modal.querySelector(".timetable-edit-btn-clear");
+  if (clearBtn) {
+    clearBtn.addEventListener("click", () => {
+      onClear(item.ci);
+      removeModal();
+    });
+  }
+
+  document.body.appendChild(overlay);
+  document.addEventListener("keydown", handleKeydown);
+  roomInput?.focus();
+}
+
+const timetableEditPlugin: Plugin<{}, TimetableStorage> = {
+  id: "timetableEdit",
+  name: "Edit Rooms & Teachers",
+  description: "Edit room and teacher names in timetable classes",
+  version: "1.0.0",
+  settings: {},
+  disableToggle: true,
+  defaultEnabled: true,
+
+  run: async (api) => {
+    const styleEl = document.createElement("style");
+    styleEl.textContent = styles;
+    document.head.appendChild(styleEl);
+
+    await api.storage.loaded;
+
+    let observer: MutationObserver | null = null;
+    let quickbarObserver: MutationObserver | null = null;
+    let lastClickedCi: number | null = null;
+    let lastClickedEntry: { roomEl: HTMLElement; teacherEl: HTMLElement; item: TimetableEntryData } | null = null;
+
+    const getOverrides = (): TimetableOverrides =>
+      api.storage.timetableOverrides ?? {};
+    const getOverridesBySubject = (): TimetableOverridesBySubject =>
+      api.storage.timetableOverridesBySubject ?? {};
+
+    const getEffectiveOverride = (
+      ci: number,
+      description: string,
+    ): { room?: string; staff?: string } | undefined =>
+      getOverrides()[String(ci)] ?? getOverridesBySubject()[description];
+
+    const processEntry = (entry: HTMLElement): void => {
+      if (entry.classList.contains("assessment") || entry.hasAttribute("data-timetable-edit-processed")) return;
+
+      const ciStr = entry.getAttribute("data-instance");
+      if (!ciStr) return;
+
+      const ci = parseInt(ciStr, 10);
+      if (isNaN(ci)) return;
+
+      const { roomEl, teacherEl } = getRoomAndTeacherElements(entry);
+      if (!roomEl && !teacherEl) return;
+
+      const titleEl = entry.querySelector(".title");
+      const description = titleEl?.textContent?.trim() ?? "";
+      const room = roomEl?.textContent?.trim() ?? "";
+      const staff = teacherEl?.textContent?.trim() ?? "";
+
+      const item: TimetableEntryData = { ci, description, room, staff };
+
+      entry.setAttribute("data-timetable-edit-processed", "true");
+
+      const override = getEffectiveOverride(ci, description);
+      if (override) {
+        if (override.room !== undefined && roomEl) roomEl.textContent = override.room;
+        if (override.staff !== undefined && teacherEl) teacherEl.textContent = override.staff;
+      }
+
+      const captureClick = (e: MouseEvent) => {
+        lastClickedCi = ci;
+        lastClickedEntry = { roomEl, teacherEl, item };
+      };
+      entry.addEventListener("click", captureClick, true);
+    };
+
+    const processAllEntries = () => {
+      document.querySelectorAll(".timetablepage .entry.class").forEach((entry) => {
+        processEntry(entry as HTMLElement);
+      });
+    };
+
+    const addEditButtonToQuickbar = (quickbar: HTMLElement) => {
+      if (quickbar.querySelector(".timetable-edit-quickbar-btn")) return;
+
+      const actions = quickbar.querySelector(".actions");
+      if (!actions) return;
+
+      const btn = document.createElement("button");
+      btn.type = "button";
+      btn.className = "uiButton timetable-edit-quickbar-btn";
+      btn.title = "Edit room and teacher";
+      btn.innerHTML = EDIT_ICON_SVG;
+
+      btn.addEventListener("click", (e) => {
+        e.preventDefault();
+        e.stopPropagation();
+        const ci = lastClickedCi;
+        const entryData = lastClickedEntry;
+        if (!ci || !entryData) return;
+
+        const qb = (e.currentTarget as HTMLElement).closest(".quickbar");
+        if (!qb) return;
+        const quickbarRoom = qb.querySelector(".meta .room")?.textContent?.trim() ?? "";
+        const quickbarTeacher = qb.querySelector(".meta .teacher")?.textContent?.trim() ?? "";
+        const quickbarTitle = qb.querySelector(".title")?.textContent?.trim() ?? "";
+        const item: TimetableEntryData = {
+          ci,
+          description: quickbarTitle || entryData.item.description,
+          room: quickbarRoom || entryData.item.room,
+          staff: quickbarTeacher || entryData.item.staff,
+        };
+
+        showEditModal(
+          item,
+          getOverrides(),
+          getOverridesBySubject(),
+          (ci, room, staff, applyToFuture) => {
+            if (applyToFuture) {
+              const bySubject = { ...getOverridesBySubject() };
+              bySubject[item.description] = {
+                room: room || undefined,
+                staff: staff || undefined,
+              };
+              api.storage.timetableOverridesBySubject = bySubject;
+            } else {
+              const current = getOverrides();
+              api.storage.timetableOverrides = {
+                ...current,
+                [String(ci)]: { room: room || undefined, staff: staff || undefined },
+              };
+            }
+            if (entryData.roomEl) entryData.roomEl.textContent = room;
+            if (entryData.teacherEl) entryData.teacherEl.textContent = staff;
+            processAllEntries();
+          },
+          (ci) => {
+            const current = getOverrides();
+            delete current[String(ci)];
+            api.storage.timetableOverrides = current;
+            const bySubject = getOverridesBySubject();
+            delete bySubject[item.description];
+            api.storage.timetableOverridesBySubject = bySubject;
+            if (entryData.roomEl) entryData.roomEl.textContent = item.room;
+            if (entryData.teacherEl) entryData.teacherEl.textContent = item.staff;
+            processAllEntries();
+          },
+        );
+      });
+
+      actions.insertBefore(btn, actions.firstChild);
+    };
+
+    const syncQuickbarFromDOM = () => {
+      const quickbar = document.querySelector(".timetablepage .quickbar.visible");
+      if (quickbar && quickbar.getAttribute("data-type") === "class") {
+        const titleEl = quickbar.querySelector(".title");
+        const roomEl = quickbar.querySelector(".meta .room");
+        const teacherEl = quickbar.querySelector(".meta .teacher");
+        if (titleEl && roomEl && teacherEl && lastClickedCi !== null && lastClickedEntry) {
+          addEditButtonToQuickbar(quickbar as HTMLElement);
+        }
+      }
+    };
+
+    const setupQuickbarObserver = () => {
+      const timetablePage = document.querySelector(".timetablepage");
+      if (!timetablePage || quickbarObserver) return;
+
+      quickbarObserver = new MutationObserver(() => {
+        const quickbar = document.querySelector(".timetablepage .quickbar.visible");
+        if (quickbar?.getAttribute("data-type") === "class") {
+          addEditButtonToQuickbar(quickbar as HTMLElement);
+        }
+      });
+
+      quickbarObserver.observe(timetablePage, {
+        childList: true,
+        subtree: true,
+        attributes: true,
+        attributeFilter: ["class"],
+      });
+    };
+
+    const handleTimetable = async () => {
+      await waitForElm(".timetablepage .entry", true, 10, 100);
+      processAllEntries();
+      setupQuickbarObserver();
+      syncQuickbarFromDOM();
+
+      const timetablePage = document.querySelector(".timetablepage");
+      if (timetablePage && !observer) {
+        observer = new MutationObserver(() => {
+          document.querySelectorAll(".timetablepage .entry.class").forEach((entry) => {
+            if (!entry.hasAttribute("data-timetable-edit-processed")) {
+              processEntry(entry as HTMLElement);
+            }
+          });
+        });
+        observer.observe(timetablePage, { childList: true, subtree: true });
+      }
+    };
+
+    const { unregister } = api.seqta.onMount(".timetablepage", handleTimetable);
+
+    return () => {
+      unregister();
+      observer?.disconnect();
+      quickbarObserver?.disconnect();
+      styleEl.remove();
+      document.querySelectorAll("[data-timetable-edit-processed]").forEach((el) => {
+        el.removeAttribute("data-timetable-edit-processed");
+      });
+      document.querySelectorAll(".timetable-edit-quickbar-btn").forEach((el) => el.remove());
+    };
+  },
+};
+
+export default timetableEditPlugin;
diff --git a/src/plugins/built-in/timetableEdit/styles.css b/src/plugins/built-in/timetableEdit/styles.css
new file mode 100644
index 00000000..ef686962
--- /dev/null
+++ b/src/plugins/built-in/timetableEdit/styles.css
@@ -0,0 +1,188 @@
+/* Timetable Edit Plugin - BetterSEQTA Plus style */
+
+/* Edit button in quickbar */
+.timetable-edit-quickbar-btn {
+  padding: 0;
+  margin: 0;
+  background: transparent !important;
+  border: none !important;
+  cursor: pointer;
+  transition: all 0.2s ease-in-out;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.timetable-edit-quickbar-btn:hover {
+  transform: scale(1.05);
+}
+
+.timetable-edit-quickbar-btn:active {
+  transform: scale(0.95);
+}
+
+.timetable-edit-quickbar-btn svg {
+  fill: currentColor;
+  width: 24px;
+  height: 24px;
+}
+
+/* Edit modal animations */
+@keyframes timetable-edit-overlay-in {
+  from {
+    opacity: 0;
+  }
+  to {
+    opacity: 1;
+  }
+}
+
+@keyframes timetable-edit-modal-in {
+  from {
+    opacity: 0;
+    transform: scale(0.95) translateY(-8px);
+  }
+  to {
+    opacity: 1;
+    transform: scale(1) translateY(0);
+  }
+}
+
+/* Edit modal overlay - fix click-through with proper stacking */
+.timetable-edit-modal-overlay {
+  position: fixed;
+  inset: 0;
+  z-index: 2147483647;
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  background: rgba(0, 0, 0, 0.5);
+  backdrop-filter: blur(4px);
+  pointer-events: auto;
+  animation: timetable-edit-overlay-in 0.2s ease-out forwards;
+}
+
+.timetable-edit-modal {
+  padding: 1rem 1.5rem;
+  margin: 0 1rem;
+  min-width: 18rem;
+  max-width: 24rem;
+  width: 100%;
+  box-sizing: border-box;
+  background: var(--background-primary);
+  border-radius: 0.75rem;
+  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
+  pointer-events: auto;
+  border: 1px solid var(--background-secondary);
+  animation: timetable-edit-modal-in 0.25s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
+}
+
+.timetable-edit-modal h3 {
+  margin: 0 0 1rem 0;
+  font-size: 1.125rem;
+  font-weight: 600;
+  color: var(--text-primary);
+}
+
+.timetable-edit-modal label {
+  display: block;
+  margin-bottom: 0.25rem;
+  font-size: 0.875rem;
+  font-weight: 500;
+  color: var(--text-primary);
+  opacity: 0.8;
+}
+
+.timetable-edit-modal input[type="text"] {
+  width: 100%;
+  min-width: 0;
+  padding: 0.5rem 1rem 0.5rem 0.75rem;
+  margin-bottom: 1rem;
+  font-size: 0.875rem;
+  border: 1px solid var(--background-secondary);
+  border-radius: 0.5rem;
+  background: var(--background-secondary);
+  color: var(--text-primary);
+  box-sizing: border-box;
+  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.15s ease;
+  user-select: text;
+  -webkit-user-select: text;
+}
+
+.timetable-edit-modal input[type="text"]:focus {
+  outline: none;
+  border-color: var(--better-main, #007bff);
+  box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
+}
+
+.timetable-edit-modal-checkbox {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  margin-bottom: 1rem;
+}
+
+.timetable-edit-modal-checkbox input {
+  width: auto;
+  margin: 0;
+}
+
+.timetable-edit-modal-checkbox label {
+  margin: 0;
+  cursor: pointer;
+}
+
+.timetable-edit-modal-actions {
+  display: flex;
+  gap: 0.75rem;
+  justify-content: flex-end;
+  margin-top: 1rem;
+  flex-wrap: wrap;
+}
+
+.timetable-edit-modal-actions button {
+  padding: 0.5rem 1rem;
+  font-size: 0.875rem;
+  font-weight: 500;
+  border-radius: 0.5rem;
+  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
+  cursor: pointer;
+}
+
+.timetable-edit-modal-actions .timetable-edit-btn-clear {
+  background: transparent;
+  border: 1px solid var(--background-secondary);
+  color: var(--text-primary);
+}
+
+.timetable-edit-modal-actions .timetable-edit-btn-clear:hover {
+  background: var(--background-secondary);
+  transform: translateY(-1px);
+}
+
+.timetable-edit-modal-actions .timetable-edit-btn-cancel {
+  background: transparent;
+  border: 1px solid var(--background-secondary);
+  color: var(--text-primary);
+}
+
+.timetable-edit-modal-actions .timetable-edit-btn-cancel:hover {
+  background: var(--background-secondary);
+  transform: translateY(-1px);
+}
+
+.timetable-edit-modal-actions .timetable-edit-btn-save {
+  background: var(--better-main, #007bff);
+  border: none;
+  color: var(--text-color, white);
+}
+
+.timetable-edit-modal-actions .timetable-edit-btn-save:hover {
+  transform: scale(1.03) translateY(-1px);
+  box-shadow: 0 4px 12px rgba(0, 123, 255, 0.35);
+}
+
+.timetable-edit-modal-actions .timetable-edit-btn-save:active {
+  transform: scale(0.98) translateY(0);
+  box-shadow: none;
+}
diff --git a/src/plugins/index.ts b/src/plugins/index.ts
index 0c4751c0..0648accb 100644
--- a/src/plugins/index.ts
+++ b/src/plugins/index.ts
@@ -2,6 +2,7 @@ import { PluginManager } from "./core/manager";
 
 // Lightweight plugins (load immediately)
 import timetablePlugin from "./built-in/timetable";
+import timetableEditPlugin from "./built-in/timetableEdit";
 import notificationCollectorPlugin from "./built-in/notificationCollector";
 import themesPlugin from "./built-in/themes";
 import animatedBackgroundPlugin from "./built-in/animatedBackground";
@@ -23,6 +24,7 @@ pluginManager.registerPlugin(animatedBackgroundPlugin);
 pluginManager.registerPlugin(assessmentsAveragePlugin);
 pluginManager.registerPlugin(notificationCollectorPlugin);
 pluginManager.registerPlugin(timetablePlugin);
+pluginManager.registerPlugin(timetableEditPlugin);
 pluginManager.registerPlugin(profilePicturePlugin);
 pluginManager.registerPlugin(assessmentsOverviewPlugin);
 pluginManager.registerPlugin(backgroundMusicPlugin);