Stewart is a small lunar impact crater that lies to the northeast of the Mare Spumans, a small lunar mare near the eastern limb of the Moon.

It was named after American astrophysicist John Quincy Stewart.

[1] It is located to the north of the crater Pomortsev, and to the southwest of the lava-flooded Dubyago.

Stewart was previously designated Dubyago Q before being named by the IAU.

This is a circular crater with a low outer rim and a level, featureless interior floor.