diff --git a/src/eslint-baseline.linux.txt b/src/eslint-baseline.linux.txt
index 4e8a6e6d2..053a342ad 100644
--- a/src/eslint-baseline.linux.txt
+++ b/src/eslint-baseline.linux.txt
@@ -1 +1 @@
-5464
+5462
diff --git a/src/eslint-baseline.txt b/src/eslint-baseline.txt
index 4e8a6e6d2..053a342ad 100644
--- a/src/eslint-baseline.txt
+++ b/src/eslint-baseline.txt
@@ -1 +1 @@
-5464
+5462
diff --git a/src/widgets/chat/chat-widget/ChatWidget.ts b/src/widgets/chat/chat-widget/ChatWidget.ts
index 8b3aaaaa9..c6ffe400e 100644
--- a/src/widgets/chat/chat-widget/ChatWidget.ts
+++ b/src/widgets/chat/chat-widget/ChatWidget.ts
@@ -432,6 +432,17 @@ export class ChatWidget extends EntityScrollerWidget<ChatMessageEntity> {
       messageElement.className = `message-row ${isCurrentUser ? 'right' : 'left'}${postingClass}`;
       // CRITICAL: Add entity ID to DOM for testing/debugging (test expects 'message-id')
       messageElement.setAttribute('message-id', message.id);
+      // A11Y (#1099 phase 2). Each message row gets a screen-reader
+      // label and role=article so the chat transcript can be navigated
+      // message-by-message instead of word-by-word. The transcript
+      // container already carries role=log + aria-live=polite from
+      // phase 1, so new messages auto-announce.
+      messageElement.setAttribute('role', 'article');
+      const ts = new Date(message.timestamp).toLocaleString();
+      messageElement.setAttribute(
+        'aria-label',
+        `${senderName} at ${ts}${message.status === 'sending' ? ', sending' : ''}`
+      );
 
       // Build message structure with DOM APIs (no innerHTML for static structure)
       const bubble = globalThis.document.createElement('div');
diff --git a/src/widgets/chat/room-list/RoomListWidget.ts b/src/widgets/chat/room-list/RoomListWidget.ts
index a074c221b..56d3a251c 100644
--- a/src/widgets/chat/room-list/RoomListWidget.ts
+++ b/src/widgets/chat/room-list/RoomListWidget.ts
@@ -13,6 +13,7 @@ import {
   html,
   reactive,
   unsafeCSS,
+  nothing,
   type TemplateResult,
   type CSSResultGroup
 } from '../../shared/ReactiveListWidget';
@@ -201,7 +202,13 @@ export class RoomListWidget extends ReactiveListWidget<RoomEntity> {
     return html`
       <div class="entity-list-container">
         ${this.renderHeader()}
-        <div class="${this.containerClass}"></div>
+        <div
+          class="${this.containerClass}"
+          ?hidden=${this.isEmpty}
+          role="listbox"
+          aria-label="Rooms and direct messages"
+        ></div>
+        ${this.isEmpty ? this.renderEmptyState() : nothing}
         ${showNewDM && hasDMs ? html`
           <div class="new-dm-btn" @click=${this.startNewDM}>+ Start a conversation</div>
         ` : ''}
@@ -210,6 +217,21 @@ export class RoomListWidget extends ReactiveListWidget<RoomEntity> {
     `;
   }
 
+  // === A11Y === (#1099 phase 2)
+  protected override getItemLabel(room: RoomEntity): string {
+    if (this.isDM(room)) {
+      const info = this.getDMDisplayInfo(room);
+      const memberCount = room.members?.length ?? 0;
+      const isGroup = memberCount > 2;
+      return isGroup
+        ? `Group DM: ${info.name}, ${memberCount} members`
+        : `Direct message with ${info.name}`;
+    }
+    const name = room.displayName ?? room.name ?? 'Room';
+    const topic = room.topic ?? '';
+    return topic ? `Room ${name} — ${topic}` : `Room ${name}`;
+  }
+
   // === FILTERING ===
   private isDM(room: RoomEntity): boolean {
     return room.type === 'direct' || (room.tags ?? []).includes('dm');
@@ -436,7 +458,7 @@ export class RoomListWidget extends ReactiveListWidget<RoomEntity> {
     this.selectRoom(room);
   }
 
-  protected override onItemClick(_item: RoomEntity): void {
-    // Handled by @click in renderItem template
+  protected override onItemClick(item: RoomEntity): void {
+    this.selectRoom(item);
   }
 }
diff --git a/src/widgets/chat/user-list/UserListWidget.ts b/src/widgets/chat/user-list/UserListWidget.ts
index 75719a1ea..52aa47f5f 100644
--- a/src/widgets/chat/user-list/UserListWidget.ts
+++ b/src/widgets/chat/user-list/UserListWidget.ts
@@ -181,7 +181,12 @@ export class UserListWidget extends ReactiveListWidget<UserEntity> {
     return html`
       <div class="entity-list-container">
         ${this.renderHeader()}
-        <div class="${this.containerClass}" ?hidden=${this.isEmpty}></div>
+        <div
+          class="${this.containerClass}"
+          ?hidden=${this.isEmpty}
+          role="listbox"
+          aria-label="Users and personas"
+        ></div>
         ${this.isEmpty ? this.renderEmptyState() : nothing}
         ${this.renderFooter()}
       </div>
@@ -202,6 +207,14 @@ export class UserListWidget extends ReactiveListWidget<UserEntity> {
     `;
   }
 
+  // === A11Y === (#1099 phase 2)
+  protected override getItemLabel(user: UserEntity): string {
+    const name = user.displayName ?? 'Unknown user';
+    const typeLabel = user.type === 'persona' ? 'persona' : user.type === 'agent' ? 'agent' : 'user';
+    const status = user.status ?? 'offline';
+    return `${name}, ${typeLabel}, ${status}`;
+  }
+
   // === ITEM RENDERING ===
   renderItem(user: UserEntity): TemplateResult {
     const displayName = user.displayName ?? 'Unknown User';
@@ -308,11 +321,22 @@ export class UserListWidget extends ReactiveListWidget<UserEntity> {
       const div = globalThis.document.createElement('div');
       div.className = 'list-item';
       div.dataset.id = user.id;
+      div.setAttribute('role', 'option');
+      div.tabIndex = 0;
+      div.setAttribute('aria-label', this.getItemLabel(user));
+      div.setAttribute('aria-selected', String(this._selectedUserId === user.id));
       render(this.renderItem(user), div);
       div.addEventListener('click', (e) => {
         e.stopPropagation();
         this.onItemClick(user);
       });
+      div.addEventListener('keydown', (e: KeyboardEvent) => {
+        if (e.key === 'Enter' || e.key === ' ') {
+          e.preventDefault();
+          e.stopPropagation();
+          this.onItemClick(user);
+        }
+      });
       return div;
     };
   }
@@ -320,6 +344,7 @@ export class UserListWidget extends ReactiveListWidget<UserEntity> {
   // === EVENT HANDLERS ===
   private handleUserClick(e: Event, user: UserEntity): void {
     if ((e.target as HTMLElement).tagName === 'BUTTON') return;
+    e.stopPropagation();
     this._selectedUserId = user.id;
     this.openUserProfile(user);
   }
@@ -406,7 +431,8 @@ export class UserListWidget extends ReactiveListWidget<UserEntity> {
   }
 
   // === SELECTION HOOK (override base) ===
-  protected override onItemClick(_item: UserEntity): void {
-    // Handled by @click in renderItem template
+  protected override onItemClick(item: UserEntity): void {
+    this._selectedUserId = item.id;
+    this.openUserProfile(item);
   }
 }
diff --git a/src/widgets/shared/ReactiveListWidget.ts b/src/widgets/shared/ReactiveListWidget.ts
index efa38cc7a..44126fc7d 100644
--- a/src/widgets/shared/ReactiveListWidget.ts
+++ b/src/widgets/shared/ReactiveListWidget.ts
@@ -125,7 +125,12 @@ export abstract class ReactiveListWidget<T extends BaseEntity> extends ReactiveE
     return html`
       <div class="list-widget">
         ${this.renderHeader()}
-        <div class="${this.containerClass}" ?hidden=${this.isEmpty}>
+        <div
+          class="${this.containerClass}"
+          ?hidden=${this.isEmpty}
+          role="listbox"
+          aria-label=${this.listTitle}
+        >
           <!-- EntityScroller populates items here -->
         </div>
         ${this.isEmpty ? this.renderEmptyState() : nothing}
@@ -142,15 +147,91 @@ export abstract class ReactiveListWidget<T extends BaseEntity> extends ReactiveE
       const div = document.createElement('div');
       div.className = 'list-item';
       div.dataset.id = item.id;
+      // ARIA listbox semantics (#1099 phase 2). The container has
+      // role="listbox" (set in subclass render overrides); each item
+      // is role="option". tabindex=0 makes items keyboard-focusable —
+      // proper roving tabindex (only the active item gets tabindex=0)
+      // is a phase-3 follow-up.
+      div.setAttribute('role', 'option');
+      div.tabIndex = 0;
+      const label = this.getItemLabel(item);
+      if (label) div.setAttribute('aria-label', label);
+      div.setAttribute('aria-selected', String(this.isSelected(item)));
       render(this.renderItem(item), div);
       div.addEventListener('click', (e) => {
         e.stopPropagation();
         this.onItemClick(item);
       });
+      // Enter or Space activates the item — same effect as a mouse click.
+      // The click handler above already handles selection updates.
+      div.addEventListener('keydown', (e: KeyboardEvent) => {
+        if (e.key === 'Enter' || e.key === ' ') {
+          e.preventDefault();
+          e.stopPropagation();
+          this.onItemClick(item);
+        }
+      });
       return div;
     };
   }
 
+  /**
+   * Accessible name for a list item. Default uses `displayName` or `name`
+   * fields if present on the entity, otherwise empty (which omits the
+   * aria-label and lets the screen reader fall back to the rendered
+   * text content). Subclasses override to provide a richer label —
+   * for example "<room name>, <member count> members".
+   */
+  protected getItemLabel(item: T): string {
+    const e = item as unknown as { displayName?: string; name?: string };
+    return e.displayName ?? e.name ?? '';
+  }
+
+  /**
+   * Keyboard navigation handler attached to the listbox container in
+   * `firstUpdated()`. ArrowDown/Up move focus to the next/previous
+   * `.list-item`, Home/End jump to first/last, Enter/Space activate.
+   * Handler is scoped to the container so it doesn't interfere with
+   * keyboard handling on sibling widgets (e.g., the chat composer).
+   */
+  private onListKeydown = (e: KeyboardEvent): void => {
+    const items = Array.from(
+      this.shadowRoot?.querySelectorAll<HTMLElement>(`.${this.containerClass} > .list-item`) ?? []
+    );
+    if (items.length === 0) return;
+
+    const active = this.shadowRoot?.activeElement as HTMLElement | null;
+    const currentIdx = active ? items.indexOf(active) : -1;
+
+    let nextIdx: number | null = null;
+    switch (e.key) {
+      case 'ArrowDown':
+        nextIdx = currentIdx < 0 ? 0 : Math.min(currentIdx + 1, items.length - 1);
+        break;
+      case 'ArrowUp':
+        nextIdx = currentIdx < 0 ? items.length - 1 : Math.max(currentIdx - 1, 0);
+        break;
+      case 'Home':
+        nextIdx = 0;
+        break;
+      case 'End':
+        nextIdx = items.length - 1;
+        break;
+      default:
+        return;
+    }
+    if (nextIdx !== null) {
+      e.preventDefault();
+      items[nextIdx].focus();
+    }
+  };
+
+  protected override firstUpdated(): void {
+    super.firstUpdated();
+    const container = this.shadowRoot?.querySelector(`.${this.containerClass}`);
+    container?.addEventListener('keydown', this.onListKeydown as EventListener);
+  }
+
   protected getLoadFunction(): LoadFn<T> {
     return async (cursor?: string, limit?: number) => {
       const result = await DataList.execute<T>({