diff --git a/model/GroupedList.php b/model/GroupedList.php
new file mode 100644
index 000000000..390be964b
--- /dev/null
+++ b/model/GroupedList.php
@@ -0,0 +1,50 @@
+<?php
+/**
+ * A list decorator that allows a list to be grouped into sub-lists by common
+ * values of a field.
+ *
+ * @package    sapphire
+ * @subpackage model
+ */
+class GroupedList extends SS_ListDecorator {
+
+	/**
+	 * @param  string $index
+	 * @return ArrayList
+	 */
+	public function groupBy($index) {
+		$result = array();
+
+		foreach ($this->list as $item) {
+			$key = is_object($item) ? $item->$index : $item[$index];
+
+			if (array_key_exists($key, $result)) {
+				$result[$key]->push($item);
+			} else {
+				$result[$key] = new ArrayList(array($item));
+			}
+		}
+
+		return $result;
+	}
+
+	/**
+	 * @param  string $index
+	 * @param  string $children
+	 * @return ArrayList
+	 */
+	public function GroupedBy($index, $children = 'Children') {
+		$grouped = $this->groupBy($index);
+		$result  = new ArrayList();
+
+		foreach ($grouped as $indVal => $list) {
+			$result->push(new ArrayData(array(
+				$index    => $indVal,
+				$children => $list
+			)));
+		}
+
+		return $result;
+	}
+
+}
diff --git a/tests/model/GroupedListTest.php b/tests/model/GroupedListTest.php
new file mode 100644
index 000000000..4307c67f3
--- /dev/null
+++ b/tests/model/GroupedListTest.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * Tests for the {@link GroupedList} list decorator.
+ *
+ * @package    sapphire
+ * @subpackage tests
+ */
+class GroupedListTest extends SapphireTest {
+
+	public function testGroupBy() {
+		$list = new GroupedList(new ArrayList(array(
+			array('Name' => 'AAA'),
+			array('Name' => 'AAA'),
+			array('Name' => 'BBB'),
+			array('Name' => 'BBB'),
+			array('Name' => 'AAA'),
+			array('Name' => 'BBB'),
+			array('Name' => 'CCC'),
+			array('Name' => 'CCC')
+		)));
+
+		$grouped = $list->groupBy('Name');
+
+		$this->assertEquals(3, count($grouped));
+		$this->assertEquals(3, count($grouped['AAA']));
+		$this->assertEquals(3, count($grouped['BBB']));
+		$this->assertEquals(2, count($grouped['CCC']));
+	}
+
+	public function testGroupedBy() {
+		$list = new GroupedList(new ArrayList(array(
+			array('Name' => 'AAA'),
+			array('Name' => 'AAA'),
+			array('Name' => 'BBB'),
+			array('Name' => 'BBB'),
+			array('Name' => 'AAA'),
+			array('Name' => 'BBB'),
+			array('Name' => 'CCC'),
+			array('Name' => 'CCC')
+		)));
+
+		$grouped = $list->GroupedBy('Name');
+		$first   = $grouped->first();
+		$last    = $grouped->last();
+
+		$this->assertEquals(3, count($first->Children));
+		$this->assertEquals('AAA', $first->Name);
+		$this->assertEquals(2, count($last->Children));
+		$this->assertEquals('CCC', $last->Name);
+	}
+
+}