British-born American mathematician and astronomer known for his theory of the motion of the Moon.

Educated at the University of Cambridge in England, Brown began there to study the motion of the Moon by a method devised by G.W. Hill of the United States. Hill had carried the process far enough to show its suitability for solving the problem, and Brown completed the theory. In 1919, after 30 years of work, Brown published his lunar tables, thereby making obsolescent those that had been in use for more than 60 years.

Brown returned to Cambridge almost every summer, but he worked chiefly in the United States. He accepted an appointment at Haverford College, Pennsylvania, in 1891, and was professor of mathematics at Yale University from 1907 until his retirement in 1932.