Maguire made his first team appearance for Aberdeen as a substitute in their final match of the 2005–06 season, where he set up John Stewart for the equaliser in a 2–2 draw against SPL champions Celtic, coincidently the team he has supported since a child, in the last game of the season.

His first starting appearance in the senior team was on 26 December 2006 against Kilmarnock, where he also scored his first senior goal for the club after 5 minutes. He has scored some vital goals including a 94th minute header against Inverness CT and twice in a 2-1 win against Falkirk just days later. On 16 July 2008, Maguire signed a three-year contract extension with the Dons which keeps the youngster at Pittodrie until the summer of 2011.

In February 2009, Aberdeen manager Jimmy Calderwood revealed that Maguire had requested to go out on loan in search of regular first team football. This request was promptly turned down. After his request of going out on loan was rejected, Maguire scored two goals in Aberdeen's 5–0 Scottish Cup victory over East Fife.

Maguire moved to Kilmarnock on loan during the January transfer window, reuniting him with former boss, Jimmy Calderwood. Maguire scored on his debut against Celtic which gave Killie their first win in 8 league games.

Mar 2nd 2010... Chris Maguire was named Clydesdale Bank Premier League Young Player of the Month after an impressive start to his career at Rugby Park.

Maguire is on loan from Aberdeen and scored three times for Jimmy Calderwood's men during February, including the winner against Celtic and another in the 3-2 victory over St Johnstone.