diff --git a/.changeset/quiet-archived-session-selection.md b/.changeset/quiet-archived-session-selection.md
new file mode 100644
index 0000000..cca770a
--- /dev/null
+++ b/.changeset/quiet-archived-session-selection.md
@@ -0,0 +1,5 @@
+---
+"@jmfederico/pi-web": patch
+---
+
+Avoid automatically reselecting archived-only sessions unless an archived session was explicitly selected, and let closing the archived section clear archived session selection.
diff --git a/src/client/src/components/PiWebApp.ts b/src/client/src/components/PiWebApp.ts
index 592ec4a..602e50b 100644
--- a/src/client/src/components/PiWebApp.ts
+++ b/src/client/src/components/PiWebApp.ts
@@ -405,6 +405,7 @@ export class PiWebApp extends LitElement {
         .collapsible=${this.isMobileNavigationLayout}
         .collapsed=${this.isNavigationSectionCollapsed("sessions")}
         .onToggleCollapsed=${() => { this.toggleNavigationSection("sessions"); }}
+        .onArchivedCollapsed=${() => { this.sessions.clearSelectionAfterArchivedCollapse(); }}
         .onStart=${() => openChatAfter(() => this.sessions.startSession())}
         .onSelect=${(session: SessionInfo) => openChatAfter(() => this.sessions.selectSession(session))}
         .onArchive=${(session: SessionInfo) => this.sessions.archiveSession(session)}
diff --git a/src/client/src/components/SessionList.ts b/src/client/src/components/SessionList.ts
index 5b923cb..f2bb2a8 100644
--- a/src/client/src/components/SessionList.ts
+++ b/src/client/src/components/SessionList.ts
@@ -30,6 +30,7 @@ export class SessionList extends LitElement {
   @property({ attribute: false }) onSelect?: (session: SessionInfo) => void;
   @property({ attribute: false }) onStart?: () => void;
   @property({ attribute: false }) onToggleCollapsed?: () => void;
+  @property({ attribute: false }) onArchivedCollapsed?: () => void;
   @state() private openMenuSessionId: string | undefined;
   @state() private menuStyle = "";
   @state() private archivedExpanded = false;
@@ -56,7 +57,8 @@ export class SessionList extends LitElement {
     if (changed.has("sessions") && this.openMenuSessionId !== undefined && !this.sessions.some((session) => session.id === this.openMenuSessionId)) this.openMenuSessionId = undefined;
     if (changed.has("collapsed") && this.collapsed) this.openMenuSessionId = undefined;
     if (changed.has("sessions") && !this.sessions.some((session) => session.archived === true)) this.archivedExpanded = false;
-    if (this.selected?.archived === true && !this.archivedExpanded) {
+    const previousSelected = changed.get("selected");
+    if (changed.has("selected") && this.selected?.archived === true && (previousSelected?.id !== this.selected.id || previousSelected.archived !== true) && !this.archivedExpanded) {
       this.archivedExpanded = true;
       void this.updateComplete.then(() => { this.scrollSelectedIntoView(); });
       return;
@@ -138,7 +140,10 @@ export class SessionList extends LitElement {
 
   private toggleArchived() {
     this.archivedExpanded = !this.archivedExpanded;
-    if (!this.archivedExpanded) this.openMenuSessionId = undefined;
+    if (!this.archivedExpanded) {
+      this.openMenuSessionId = undefined;
+      this.onArchivedCollapsed?.();
+    }
   }
 
   private scrollSelectedIntoView(): void {
diff --git a/src/client/src/controllers/sessionController.test.ts b/src/client/src/controllers/sessionController.test.ts
index f8d8947..a59c984 100644
--- a/src/client/src/controllers/sessionController.test.ts
+++ b/src/client/src/controllers/sessionController.test.ts
@@ -4,6 +4,7 @@ import { loadCachedNewSessions, markCachedNewSessionInfo, rememberCachedNewSessi
 import { initialAppState, type AppState } from "../appState";
 import { loadDraft, saveDraft } from "../promptDraftStorage";
 import { SessionController, type SessionEventSocket } from "./sessionController";
+import { InMemorySessionSelectionMemory } from "./sessionSelection";
 
 class MemoryStorage implements Storage {
   private readonly values = new Map<string, string>();
@@ -131,4 +132,58 @@ describe("SessionController", () => {
     expect(loadCachedNewSessions().map((session) => session.id)).toEqual([replacementSession.id]);
     expect(urlUpdates).toEqual([{ replace: true }]);
   });
+
+  it("forgets the selected active session when archiving leaves only archived sessions", async () => {
+    let state: AppState = { ...initialAppState(), selectedWorkspace: workspace, sessions: [oldSession] };
+    const urlUpdates: ({ replace?: boolean | undefined } | undefined)[] = [];
+    const api: typeof defaultApi = {
+      ...defaultApi,
+      archive: () => Promise.resolve({ archived: true }),
+      messages: () => Promise.resolve(emptyPage),
+      status: (sessionId) => Promise.resolve(status(sessionId)),
+    };
+    const controller = new SessionController(
+      () => state,
+      (patch) => { state = { ...state, ...patch }; },
+      (options) => { urlUpdates.push(options); },
+      new InMemorySessionSelectionMemory(),
+      { api, socket: new FakeSocket() },
+    );
+
+    await controller.selectSession(oldSession, { updateUrl: false });
+    await controller.archiveSession();
+
+    expect(state.selectedSession).toBeUndefined();
+    expect(state.sessions).toHaveLength(1);
+    expect(state.sessions[0]).toMatchObject({ ...oldSession, archived: true });
+    expect(typeof state.sessions[0]?.archivedAt).toBe("string");
+    expect(controller.preferredSession(workspace.path, state.sessions, undefined)).toBeUndefined();
+    expect(urlUpdates).toEqual([undefined]);
+  });
+
+  it("forgets archived selections when the archived section collapse clears selection", async () => {
+    const archivedSession = { ...oldSession, archived: true, archivedAt: "later" };
+    let state: AppState = { ...initialAppState(), selectedWorkspace: workspace, sessions: [archivedSession] };
+    const urlUpdates: ({ replace?: boolean | undefined } | undefined)[] = [];
+    const api: typeof defaultApi = {
+      ...defaultApi,
+      messages: () => Promise.resolve(emptyPage),
+    };
+    const controller = new SessionController(
+      () => state,
+      (patch) => { state = { ...state, ...patch }; },
+      (options) => { urlUpdates.push(options); },
+      new InMemorySessionSelectionMemory(),
+      { api, socket: new FakeSocket() },
+    );
+
+    await controller.selectSession(archivedSession, { updateUrl: false });
+    expect(controller.preferredSession(workspace.path, state.sessions, undefined)).toBe(archivedSession);
+
+    controller.clearSelectionAfterArchivedCollapse();
+
+    expect(state.selectedSession).toBeUndefined();
+    expect(controller.preferredSession(workspace.path, state.sessions, undefined)).toBeUndefined();
+    expect(urlUpdates).toEqual([undefined]);
+  });
 });
diff --git a/src/client/src/controllers/sessionController.ts b/src/client/src/controllers/sessionController.ts
index 15ebcef..7361572 100644
--- a/src/client/src/controllers/sessionController.ts
+++ b/src/client/src/controllers/sessionController.ts
@@ -5,7 +5,7 @@ import { clearDraft, moveDraft } from "../promptDraftStorage";
 import { ChatTranscriptStore } from "../chatTranscriptStore";
 import { isShellInput } from "../inputModes";
 import { SessionSocket, type GlobalSessionEvent, type SessionUiEvent } from "../sessionSocket";
-import { InMemorySessionSelectionMemory, markSessionArchived, selectPreferredSession, selectionAfterArchivingSession, type SessionSelectionMemory } from "./sessionSelection";
+import { InMemorySessionSelectionMemory, markSessionArchived, selectPreferredSession, selectionAfterArchivingSession, shouldDeselectAfterArchivedCollapse, type SessionSelectionMemory } from "./sessionSelection";
 import type { GetState, SetState, UpdateUrl } from "./types";
 
 const MESSAGE_PAGE_SIZE = 100;
@@ -55,12 +55,27 @@ export class SessionController {
   }
 
   clearActiveSession() {
+    this.selectionSeq += 1;
     this.socket.close();
     this.catchupStreamSessionId = undefined;
     this.clearPendingTranscriptEvents();
     this.setState({ selectedSession: undefined, messages: [], messagePageStart: 0, messagePageTotal: 0, isLoadingEarlierMessages: false, isReceivingPartialStream: false, status: undefined, activity: undefined });
   }
 
+  deselectSession(options?: { forgetRememberedSelection?: boolean | undefined; updateUrl?: boolean | undefined }) {
+    const state = this.getState();
+    const cwd = state.selectedSession?.cwd ?? state.selectedWorkspace?.path;
+    if (options?.forgetRememberedSelection === true && cwd !== undefined) this.sessionSelection.forgetWorkspace(cwd);
+    this.clearActiveSession();
+    if (options?.updateUrl !== false) this.updateUrl();
+  }
+
+  clearSelectionAfterArchivedCollapse(): void {
+    const state = this.getState();
+    if (!shouldDeselectAfterArchivedCollapse(state.sessions, state.selectedSession)) return;
+    this.deselectSession({ forgetRememberedSelection: true });
+  }
+
   async startSession() {
     const workspace = this.getState().selectedWorkspace;
     if (!workspace) return;
@@ -217,10 +232,7 @@ export class SessionController {
       this.setState({ sessions });
 
       if (selectionChange.type === "select") await this.selectSession(selectionChange.session);
-      else if (selectionChange.type === "clear") {
-        this.clearActiveSession();
-        this.updateUrl();
-      }
+      else if (selectionChange.type === "clear") this.deselectSession({ forgetRememberedSelection: true });
     } catch (error) {
       this.setState({ error: String(error) });
     }
diff --git a/src/client/src/controllers/sessionSelection.test.ts b/src/client/src/controllers/sessionSelection.test.ts
index 2518349..1d656be 100644
--- a/src/client/src/controllers/sessionSelection.test.ts
+++ b/src/client/src/controllers/sessionSelection.test.ts
@@ -1,6 +1,6 @@
 import { describe, expect, it } from "vitest";
 import type { SessionInfo } from "../api";
-import { InMemorySessionSelectionMemory, markSessionArchived, selectPreferredSession, selectionAfterArchivingSession } from "./sessionSelection";
+import { InMemorySessionSelectionMemory, markSessionArchived, selectPreferredSession, selectionAfterArchivingSession, shouldDeselectAfterArchivedCollapse } from "./sessionSelection";
 
 describe("selectPreferredSession", () => {
   it("prefers an explicit target session by id", () => {
@@ -21,12 +21,24 @@ describe("selectPreferredSession", () => {
     expect(selectPreferredSession(sessions, { latestSessionId: "s2" })?.id).toBe("s2");
   });
 
+  it("does not select an archived session without an explicit or remembered selection", () => {
+    const sessions = [{ ...testSession("s1"), archived: true }];
+
+    expect(selectPreferredSession(sessions)).toBeUndefined();
+  });
+
   it("can remember an archived selected session", () => {
     const sessions = [{ ...testSession("s1"), archived: true }, testSession("s2")];
 
     expect(selectPreferredSession(sessions, { latestSessionId: "s1" })?.id).toBe("s1");
   });
 
+  it("can remember an archived selected session when only archived sessions remain", () => {
+    const sessions = [{ ...testSession("s1"), archived: true }];
+
+    expect(selectPreferredSession(sessions, { latestSessionId: "s1" })?.id).toBe("s1");
+  });
+
   it("falls back to the first active session when the remembered session no longer exists", () => {
     const sessions = [{ ...testSession("s1"), archived: true }, testSession("s2")];
 
@@ -68,6 +80,18 @@ describe("markSessionArchived", () => {
   });
 });
 
+describe("shouldDeselectAfterArchivedCollapse", () => {
+  it("deselects archived selections only when no active sessions remain", () => {
+    const archived = { ...testSession("archived"), archived: true };
+    const active = testSession("active");
+
+    expect(shouldDeselectAfterArchivedCollapse([archived], archived)).toBe(true);
+    expect(shouldDeselectAfterArchivedCollapse([archived, active], archived)).toBe(false);
+    expect(shouldDeselectAfterArchivedCollapse([archived], undefined)).toBe(false);
+    expect(shouldDeselectAfterArchivedCollapse([archived], active)).toBe(false);
+  });
+});
+
 describe("selectionAfterArchivingSession", () => {
   it("leaves selection unchanged when archiving an unselected session", () => {
     expect(selectionAfterArchivingSession([testSession("s1"), testSession("s2")], "s1", "s2")).toEqual({ type: "unchanged" });
diff --git a/src/client/src/controllers/sessionSelection.ts b/src/client/src/controllers/sessionSelection.ts
index a12fe4e..7d199e6 100644
--- a/src/client/src/controllers/sessionSelection.ts
+++ b/src/client/src/controllers/sessionSelection.ts
@@ -32,6 +32,11 @@ export function selectPreferredSession(sessions: SessionInfo[], options?: { targ
   return sessions.find((session) => session.archived !== true);
 }
 
+export function shouldDeselectAfterArchivedCollapse(sessions: SessionInfo[], selectedSession: SessionInfo | undefined): boolean {
+  if (selectedSession?.archived !== true) return false;
+  return !sessions.some((session) => session.archived !== true);
+}
+
 function sessionByIdOrPrefix(sessions: SessionInfo[], sessionId: string): SessionInfo | undefined {
   return sessions.find((session) => session.id === sessionId || session.id.startsWith(sessionId));
 }