William Allen Miller (December 17 1817 – September 30 1870) was a British chemist.

Although he was a chemist, his major contribution was to astronomy, or more specifically spectroscopy, which was a very new field at the time.

He won the Gold Medal of the Royal Astronomical Society in 1867 jointly with William Huggins, for their spectroscopic study of the composition of stars.

The Miller crater on the Moon is named after him.