John Browne joined BP in 1966 as a university apprentice. Between 1969 and 1983, he held a variety of exploration and production posts in Anchorage, New York, San Francisco, London and Canada. In 1984 he became group treasurer and chief executive of BP Finance International. In April 1986, he took up the position of executive vice president and chief financial officer of The Standard Oil Company in Cleveland, Ohio.

In 1987, following the BP/Standard merger, in addition to his position as executive vice president and chief financial officer of BP America, he was appointed chief executive officer of Standard Oil Production Company. In 1989, he became managing director and chief executive officer of BP Exploration based in London.

In September 1991, he joined the board of BP as a managing director. He was appointed group chief executive on June 10, 1995. Following the merger of BP and Amoco, he became group chief executive of BP Amoco on December 31, 1998.

In 1999, the Royal Academy of Engineering awarded Browne the Prince Philip Medal for his outstanding contribution to the field of Engineering. He was knighted in the 1998 Queen's Birthday Honours and made a life peer in 2001.