He was North Melbourne's third round draft selection in the 2005 AFL Draft, number 43 overall, from the East Fremantle Football Club in the WAFL.
He received a nomination for the NAB Rising Star for his performance against Geelong in Round 17, 2006 when he managed 25 possessions and a goal.
Swallow's form improved during the 2007 season, consistently gaining high numbers of disposals each week. This culminated in the spectacular 1-point win over Melbourne in Round 9 in which he scored the winning goal.
Swallow took a step backwards in 2008 though, playing most of the season in the VFL with question marks over his disposal and awareness.
2009: Syd Barker Medallist
But he was back to his best in 2009 returning to the side to be one of North's finest throughout the season. His disposal has notably improved, and he has worked on all aspects of his game to play every game, and is now recognised as one of the best tacklers and clearance players in the North Melbourne side, and the AFL. On October 2, 2009, Swallow was awarded the Syd Barker Medal by North Melbourne for being the club's best and fairest player for the year.
He had another terrific season in 2010 playing all 22 games for the second consecutive season and finishing just one vote behind Brent Harvey and Brady Rawlings for the Syd Barker Medal.
In 2011, he would have arguably his best season to date again playing every game and taking home his second Syd Barker Medal which he shared with Daniel Wells. He would also be one of four North Melbourne players selected in the 40 man All Australian squad however he missed out on being selected in the final 22. He would however be selected as part of Australian squad for the International Rules series against Ireland.
In February 2012, Swallow was announced captain of North Melbourne Football Club replacing Brent Harvey. As a captain, Andrew Swallow capped off a fantastic year to win the Syd Barker Medal with 60 votes becoming a three time Syd Barker Medalist.