diff --git a/pytato/transform.py b/pytato/transform.py
index 4a838b5a2ffb867ba99d4ea913f3709110c003f2..ce7552671cedc70e792396cb1a8e4997d4d00275 100644
--- a/pytato/transform.py
+++ b/pytato/transform.py
@@ -559,6 +559,20 @@ class CachedWalkMapper(WalkMapper):
 # }}}
 
 
+# {{{ TopoSortMapper
+
+class TopoSortMapper(CachedWalkMapper):
+    """A mapper that creates a list of nodes in topological order."""
+
+    def __init__(self) -> None:
+        super().__init__()
+        self.topological_order = []
+
+    def post_visit(self, expr: Any) -> bool:
+        self.topological_order.append(expr)
+
+# }}}
+
 # {{{ mapper frontends
 
 def copy_dict_of_named_arrays(source_dict: DictOfNamedArrays,
diff --git a/test/test_pytato.py b/test/test_pytato.py
index 5c3fdb519778891a2c5b1e6596c8b58570f6ecd1..78a8b2068728e605f1efaadebc714884eefb94a8 100755
--- a/test/test_pytato.py
+++ b/test/test_pytato.py
@@ -278,6 +278,27 @@ def test_dict_of_named_arrays_comparison():
     assert dict1 != dict4
 
 
+def test_toposortmapper():
+    n = pt.make_size_param("n")
+    array = pt.make_placeholder(name="array", shape=n, dtype=np.float64)
+    stack = pt.stack([array, 2*array, array + 6])
+    y = stack @ stack.T
+
+    tm = pt.transform.TopoSortMapper()
+    tm(y)
+
+    from pytato.array import (AxisPermutation, IndexLambda, MatrixProduct,
+                              Placeholder, SizeParam, Stack)
+
+    assert isinstance(tm.topological_order[0], SizeParam)
+    assert isinstance(tm.topological_order[1], Placeholder)
+    assert isinstance(tm.topological_order[2], IndexLambda)
+    assert isinstance(tm.topological_order[3], IndexLambda)
+    assert isinstance(tm.topological_order[4], Stack)
+    assert isinstance(tm.topological_order[5], AxisPermutation)
+    assert isinstance(tm.topological_order[6], MatrixProduct)
+
+
 if __name__ == "__main__":
     if len(sys.argv) > 1:
         exec(sys.argv[1])