The 2017–18 Fairfield Stags men's basketball team represented Fairfield University during the 2017–18 NCAA Division I men's basketball season. The Stags, led by seventh-year head coach Sydney Johnson, played their home games at Webster Bank Arena, with three games at Alumni Hall, as members of the Metro Atlantic Athletic Conference. They finished the season 17–16 overall, 9–9 in MAAC play to finish in a tie for fifth place. As the No. 6 seed at the MAAC tournament, they defeated No. 11 seed Marist, upset No. 3 seed Niagara and No. 7 seed Quinnipiac to advance to the championship game where they lost to Iona.