Kirby made his debut in the FAI Super Cup pre-season tournament, and scored twice on the opening day of the league season in a 4–1 defeat of Cork City. He played in the club's first appearances in European competition, the qualifying round of the 2001–02 UEFA Cup, against Litex Lovech, which Longford lost in stoppage time in the second leg in Bulgaria. Kirby scored six goals from 40 appearances in all competitions as Longford finished ninth in the League. The Premier Division was to drop from twelve to ten teams for the transitional 2002–03 League of Ireland season, so Longford had to play-off against First Division runners-up Finn Harps to retain their top-flight status. The scores were level after two legs, and Longford won 6–5 on penalties.