diff --git a/src/transforms/on-selection.js b/src/transforms/on-selection.js
index eb1f5b67d..ecbc15180 100644
--- a/src/transforms/on-selection.js
+++ b/src/transforms/on-selection.js
@@ -20,6 +20,22 @@ Transforms.select = (transform, properties) => {
   transform.setSelectionOperation(properties)
 }
 
+/**
+ * Selects the whole selection.
+ *
+ * @param {Transform} transform
+ * @param {Object} properties
+ */
+
+Transforms.selectAll = (transform) => {
+  const { state } = transform
+  const { document, selection } = state
+  const next = selection
+    .moveToRangeOf(document)
+    .focus()
+  transform.setSelectionOperation(next)
+}
+
 /**
  * Snapshot the current selection.
  *
diff --git a/test/transforms/fixtures/on-selection/select-all/basic/index.js b/test/transforms/fixtures/on-selection/select-all/basic/index.js
new file mode 100644
index 000000000..df4b287ba
--- /dev/null
+++ b/test/transforms/fixtures/on-selection/select-all/basic/index.js
@@ -0,0 +1,24 @@
+
+import assert from 'assert'
+
+export default function (state) {
+  const { selection } = state
+
+  const next = state
+    .transform()
+    .selectAll(selection)
+    .apply()
+
+  const sel = selection.merge({
+    anchorKey: '0',
+    anchorOffset: 0,
+    focusKey: '4',
+    focusOffset: 5,
+    isFocused: true
+  })
+
+  assert.deepEqual(
+    next.selection.toJS(),
+    sel.toJS()
+  )
+}
diff --git a/test/transforms/fixtures/on-selection/select-all/basic/input.yaml b/test/transforms/fixtures/on-selection/select-all/basic/input.yaml
new file mode 100644
index 000000000..2a7e1afb1
--- /dev/null
+++ b/test/transforms/fixtures/on-selection/select-all/basic/input.yaml
@@ -0,0 +1,17 @@
+
+nodes:
+  - kind: block
+    type: paragraph
+    nodes:
+      - kind: text
+        text: one
+  - kind: block
+    type: paragraph
+    nodes:
+      - kind: text
+        text: two
+  - kind: block
+    type: paragraph
+    nodes:
+      - kind: text
+        text: three