Chapman played with North Coburg Saints Football Club which merged with Fawkner Park to become Northern Saints Football Club in the EDFL, he played with the Calder Cannons in the under 18 TAC Cup competition.

He played 4 games, making his debut in round 12, 2000 against Collingwood, and kicked his first goal in the Elimination Final against Hawthorn, he finished 3rd in the Carji Greeves Medal.

At the end of the 2003 season Chapman would be named best team and constructive player, he would also finish 8th in Geelong's Best and Fairest.

Chapman capped off his season by kicking 4 goals and taking an all-time great mark on the members flank in the 2007 AFL Grand Final helping his team claim a record 119-point victory over Port Adelaide.

Geelong won the McClelland Trophy for the second year in a row, Chapman had 22 possessions and 1 goal, in the 2008 AFL Grand Final loss to Hawthorn by 26 points.

At the start of the 2009 season, Geelong won the AFL Pre-Season Premiership defeating Collingwood by 76 points.

Geelong defeated St Kilda by 12 points in the 2009 AFL Grand Final, Chapman kicked the winning goal, and was also the winner of the Norm Smith Medal.

Chapman would make the All-Australian team for the second year in a row in 2010 where he played 21 games for the season booting 23 goals.

Geelong would finish 2nd on the ladder and go all the way to the Preliminary Final but were eliminated by Collingwood after losing by 41 points.

For the fourth time in five years they made the Grand Final, where Chapman capped off his season with his third Premiership defeating Collingwood by 38 points.

[2] The Geelong champion couldn't have started his career at the Bombers any better, kicking four goals to lead Essendon to a round 1 win over North Melbourne.