Selwyn Richardson was born in Port of Spain in 1935. His school life began at the Mayaro Primary School where he also taught as a student teacher. He graduated to the Tranquility Boys Intermediate School and then moved to St. Mary's College. He attended Gray's Inn in London where he pursued Law. Richardson began his career as a police officer and later joined the Royal Air Force in England.

He returned to Trinidad and Tobago where he joined the PNM and was involved in organizing for the party. Following the 1976 General Elections, Prime Minister Dr. Williams appointed him a Senator and the Attorney General, a position he continued to hold under Prime Minister George Chambers who succeeded Dr. Williams, at his death. Mr. Richardson did not contest the 1981 elections and in fact resigned from the PNM in 1986 when he joined the NAR. He won the Ortoire/ Mayaro seat as a candidate for the NAR which won the 1986 elections. He was appointed to serve his second stint as Attorney General by then Prime Minister ANR Robinson. He served as Minister of National Security from March 1989 to January 1991 and was one of the hostages held in Parliament during the attempted coup. Selwyn Richardson was shot dead outside his Cascade home in 1995. He was 59 years old.