William Phillips Jr. (March 30, 1750 – May 26, 1827) was a Boston merchant, politician and philanthropist.

[2] Phillips was elected the tenth lieutenant governor of Massachusetts, serving from 1812 to 1823.

He drafted the letter inviting New England Governors to send delegates to the Hartford Convention of 1815.

[1] Phillips married Miriam Mason (1754–1823) on September 13, 1774, in Norwich, Massachusetts.

Phillips was the grandfather of Samuel H. Walley who was a U.S. Representative from Massachusetts.