diff --git a/crates/ely_browser_core/src/state/commands.rs b/crates/ely_browser_core/src/state/commands.rs
index 0fb0128..71cc928 100644
--- a/crates/ely_browser_core/src/state/commands.rs
+++ b/crates/ely_browser_core/src/state/commands.rs
@@ -213,6 +213,9 @@ impl BrowserCore {
                 Ok(self.set_active_tab_group_collapsed(false)?.is_some())
             }
             "ungroup-tab" | "ungroup tab" => self.ungroup_active_tab(),
+            "sleep-tab-group" | "sleep tab group" | "discard-tab-group" | "discard tab group" => {
+                Ok(self.discard_active_tab_group()?.is_some())
+            }
             "downloads" | "open-downloads" | "open downloads" => {
                 self.open_tab(downloads_url()?);
                 Ok(true)
diff --git a/crates/ely_browser_core/src/state/tab_groups.rs b/crates/ely_browser_core/src/state/tab_groups.rs
index 60974af..f733c59 100644
--- a/crates/ely_browser_core/src/state/tab_groups.rs
+++ b/crates/ely_browser_core/src/state/tab_groups.rs
@@ -80,6 +80,19 @@ impl BrowserCore {
         Ok(true)
     }
 
+    pub fn discard_active_tab_group(&mut self) -> Result<Option<usize>, CoreError> {
+        let Some(group_id) = self.active_tab_group_id()? else {
+            return Ok(None);
+        };
+        let tab_ids = self.active_space_group_tab_ids(&group_id);
+
+        for tab_id in &tab_ids {
+            self.discard_tab(tab_id)?;
+        }
+
+        Ok(Some(tab_ids.len()))
+    }
+
     pub fn split_active_tab_group(&mut self) -> Result<Option<SplitId>, CoreError> {
         let Some(group_id) = self.active_tab_group_id()? else {
             return Ok(None);
@@ -269,6 +282,10 @@ impl BrowserCore {
         )
     }
 
+    fn active_space_group_tab_ids(&self, group_id: &TabGroupId) -> Vec<TabId> {
+        self.active_space_group_tabs(group_id).iter().map(|tab| tab.id().clone()).collect()
+    }
+
     fn split_pane_space_id(
         &self,
         split_id: &SplitId,
diff --git a/crates/ely_browser_core/tests/tab_groups.rs b/crates/ely_browser_core/tests/tab_groups.rs
index 07856e8..a7ebc9d 100644
--- a/crates/ely_browser_core/tests/tab_groups.rs
+++ b/crates/ely_browser_core/tests/tab_groups.rs
@@ -1,7 +1,7 @@
 use std::error::Error;
 
 use ely_browser_core::{BrowserCore, CoreError, InitialBrowserConfig};
-use ely_domain::{CommandIntent, MAX_SPLIT_PANES, SplitAxis, UrlText};
+use ely_domain::{CommandIntent, MAX_SPLIT_PANES, SplitAxis, TabState, UrlText};
 
 #[test]
 fn group_active_tab_creates_visible_space_group() -> Result<(), Box<dyn Error>> {
@@ -167,6 +167,42 @@ fn auto_group_domains_preserves_existing_manual_groups() -> Result<(), Box<dyn E
     Ok(())
 }
 
+#[test]
+fn sleep_tab_group_command_discards_active_group_tabs() -> Result<(), Box<dyn Error>> {
+    let mut core = BrowserCore::new(InitialBrowserConfig::ely_defaults()?)?;
+    let ungrouped_tab_id = core.open_tab(UrlText::parse("https://servo.org")?);
+    let first_group_tab_id = core.open_tab(UrlText::parse("https://example.com/a")?);
+    core.group_active_tab("Docs")?;
+    let second_group_tab_id = core.open_tab(UrlText::parse("https://example.com/b")?);
+    core.group_active_tab("Docs")?;
+
+    core.set_command_query(">sleep-tab-group");
+    let intent = core.submit_command()?;
+    let snapshot = core.snapshot()?;
+
+    assert_eq!(intent, Some(CommandIntent::Command("sleep-tab-group".to_string())));
+    assert_eq!(snapshot.command_query, "");
+    assert_eq!(tab_state(&snapshot, &first_group_tab_id), Some(&TabState::Discarded));
+    assert_eq!(tab_state(&snapshot, &second_group_tab_id), Some(&TabState::Discarded));
+    assert_eq!(tab_state(&snapshot, &ungrouped_tab_id), Some(&TabState::Ready));
+    Ok(())
+}
+
+#[test]
+fn sleep_tab_group_command_preserves_query_without_active_group() -> Result<(), Box<dyn Error>> {
+    let mut core = BrowserCore::new(InitialBrowserConfig::ely_defaults()?)?;
+    let tab_id = core.open_tab(UrlText::parse("https://example.com")?);
+
+    core.set_command_query(">sleep-tab-group");
+    let intent = core.submit_command()?;
+    let snapshot = core.snapshot()?;
+
+    assert_eq!(intent, Some(CommandIntent::Command("sleep-tab-group".to_string())));
+    assert_eq!(snapshot.command_query, ">sleep-tab-group");
+    assert_eq!(tab_state(&snapshot, &tab_id), Some(&TabState::Ready));
+    Ok(())
+}
+
 #[test]
 fn tab_group_collapse_commands_update_active_group() -> Result<(), Box<dyn Error>> {
     let mut core = BrowserCore::new(InitialBrowserConfig::ely_defaults()?)?;
@@ -333,3 +369,10 @@ fn tab_group_id<'a>(
 ) -> Option<&'a ely_domain::TabGroupId> {
     snapshot.tabs.iter().find(|tab| tab.id() == tab_id).and_then(|tab| tab.group_id())
 }
+
+fn tab_state<'a>(
+    snapshot: &'a ely_browser_core::BrowserSnapshot,
+    tab_id: &ely_domain::TabId,
+) -> Option<&'a TabState> {
+    snapshot.tabs.iter().find(|tab| tab.id() == tab_id).map(|tab| tab.state())
+}
diff --git a/docs/ui-shell.md b/docs/ui-shell.md
index f17d938..143dae6 100644
--- a/docs/ui-shell.md
+++ b/docs/ui-shell.md
@@ -86,3 +86,20 @@ Domain auto grouping keeps manual groups intact and groups matching ungrouped ho
 │     servo.org                │                                               │
 └──────────────────────────────┴───────────────────────────────────────────────┘
 ```
+
+Group sleep applies the sleeping state to every tab in the active group:
+
+```text
+┌──────────────────────────────────────────────────────────────────────────────┐
+│ ELY Browser   [ >sleep-tab-group............................. ] [pin] [*] [+] │
+├──────────────────────────────┬───────────────────────────────────────────────┤
+│ Tabs                         │  Sleeping Tab                                 │
+│   [folder] Docs              │  Sleeping https://example.com/b               │
+│     2 tabs - Expanded        │                                               │
+│     example.com              │  URL      https://example.com/b               │
+│       example.com            │  Title    example.com                         │
+│     example.com              │  Session  Page session remains attached       │
+│       example.com            │                                               │
+│   servo.org                  │  [Restore]                                    │
+└──────────────────────────────┴───────────────────────────────────────────────┘
+```