Maguire started to play football at amateur club Theole, in his native town of Tiel. Here he was scouted by FC Den Bosch. At the age of 16, he joined FC Den Bosch's first squad. He moved on to FC Utrecht in 2008.
He joined Norwegian team Sarpsborg 08 FF in the summer of 2015.
International career
Maguire represented the Republic of Ireland Under-16 and the Netherlands Under-19 teams, since his father is Irish, Maguire can still represent either the Netherlands and the Republic of Ireland at senior competitive level.
On 27 January 2009, Barry Maguire was called up to the Republic of Ireland Under 21 squad for the first time, but he rejected the invitation the following day. In September 2010 he declared himself eager to represent Ireland.