The men's varsity soccer program was undefeated in its 1959 inaugural season and has demonstrated success and sportsmanship ever since. The 1978 team finished 11-2-1 and won the ECAC New England Division II/III Championship. In 1990 the team finished with a 12-0-2 record and a number one ranking in New England Division III. After a semifinal ECAC tournament appearance in 1992, Colby finished 16-1-1, and in 1993 the Mules captured the ECAC New England Division III title.
The squad also received the Fair Play Award for Sportsmanship from the New England Intercollegiate Soccer League, its third sportsmanship honor in four years. In 1994 the Mules compiled a 10-2-2 regular season record and reached the semifinals of the ECAC tournament. The 1998 team finished at 8-5-1 and advanced to the ECAC quarterfinals.
The past few years Colby teams have earned academic honors from the National Soccer Coaches Association of America and from the NESCAC. The team has made the NESCAC playoffs the past three years (2009-2011).