He obtained a student deferment from the Vietnam War draft, and in 1965 graduated from the University of Virginia. Hume first worked for the now-defunct Hartford Times, and later for United Press International and the Baltimore Evening Sun. From 1970 to 1972, Hume worked for the syndicated columnist Jack Anderson.

Prior to joining the Fox News Channel, Brit Hume worked for 23 years at ABC News. He was chief White House correspondent from 1987 through 1996. Hume joined ABC in 1973 as a consultant for the network's documentary division and was named a Washington correspondent in 1976. He was later promoted to Capitol Hill correspondent and reported on Congress until 1988. In 1991 Hume won an Emmy Award for his Gulf War coverage. He was also twice named "Best in the Business" as a White House correspondent by the American Journalism Review. During his time at ABC, Hume worked on programs that included World News Tonight With Peter Jennings, Nightline and This Week.

Hume has published two books: His 1971 work, Death and the Mines: Rebellion and Murder in the United Mine Workers and the 1976 Inside Story, a memoir of his Jack Anderson days. Hume has contributed to such publications as Harper's, The Atlantic, The New Republic and The Weekly Standard.

As a reporter for Anderson's column, Hume uncovered an internal corporate memo indicating that the 1971 Republican National Convention had been underwritten by ITT and that in exchange an antitrust case had been dropped by the Richard Nixon administration shortly thereafter. Later Anderson published a series classified documents indicating the Nixon administration, contrary to its public pronouncements, had tipped in favor of Pakistan during the Indo-Pakistani War of 1971. After those revelations Anderson and his staff, including Hume and his wife and children, were placed under surveillance by the CIA. The agents codenamed Hume "Eggnog" and observed he and his family going about their daily business. This came to light during the Gerald Ford administration in congressional hearings, and as the result of a Freedom of Information Act lawsuit.

Hume is married to Rhoda Kim Schiller Hume, Fox News' vice president and Washington bureau chief. Prior to joining Fox in 1995, she worked for 14 years at ABC News, where she was a producer for World News Tonight and This Week with David Brinkley. Brit and Kim Hume reside in Washington, DC.

Brit Hume's son, Washington journalist Sandy Hume was a reporter for The Hill newspaper. Sandy Hume broke the story of the aborted 1997 coup against House Speaker Newt Gingrich. In February 1998 Sandy Hume committed suicide with a hunting rifle. The National Press Club honors his memory with the annual Sandy Hume Memorial Award for Excellence in Political Journalism.