Barry Cowan was born in Southport on August 25, 1974.
He achieved his best ranking in singles on September 11, 2000 with 162nd position, while in doubles he became 136th in the ATP rankings on August 9, 1999.
In 2001, paired with Moses Navarra, he reached the final of the Chennai Open; on that occasion they were defeated by the pair formed by Byron and Wayne Black with a score of 4-6, 3-6. In the same year, at Wimbledon, in the second round, he led the number one seed, the American Pete Sampras, up to the fifth set; the match ended with the result of 3-6, 2-6, 7-65, 6-4, 3-6, in favor of Sampras.
He was called up to the British Davis Cup team only once in 2001, in the match against Ecuador; when the match was won, he played, losing it, the fourth singles against Luis Morejon.
A left-hander, Cowan was a versatile sportsman in his junior years; he represented the North of England at under-15 level hockey and is also a member of Ormskirk Golf Club. After success in junior tournaments, Cowan first competed at the All England Club in 1994 as a wild card, losing in the first round to that year's French Open champion Sergi Bruguera in four sets.