Frum was born in Toronto, Canada in 1960. He received a simultaneous BA and MA in history from Yale in 1982. He was appointed a visiting lecturer in history at Yale in 1986; in 1987, he graduated cum laude from the Harvard Law School, where he served as president of the Federalist Society.
Frum was an editor on the editorial page of the Wall Street Journal from 1989 until 1992. In 1992-1994, Frum wrote the law column at Forbes magazine. Between 1994 and 2001, Frum was a senior fellow at the Manhattan Institute for Public Policy Research.
Frum lives in Washington, D.C., with his wife, journalist and novelist Danielle Crittenden Frum, and their three children. « less