A product of the Queen's Park youth system, Barry made his first team debut for the Glasgow side in a 2-2 draw with Stranraer at the start of the 2008-09 season, and became a regular at left back as the season went on. He made 37 appearances, including the narrow defeat to Celtic at Parkhead in the Scottish Cup, and scored 2 goals in his first season in the Second Division.

Although Queen's Park were relegated to the Third Division, Barry continued to improve, and scored an impressive 9 goals in his 39 games during the 2009-10 season, winning their player of the year award in the process.

Barry had been the subject of interest from several clubs, both in the Championship in England and the SPL before he signed for United on 20 June 2010. His performances had been monitored by Peter Houston, who moved quickly to bring him to Tannadice as soon as his availability was known.

His first team debut was not one to be remembered, coming off the bench in the disastrous 4-0 defeat to Inverness CT in the first home game of the season. Throughout his first season at Tannadice he was used as able cover for both Paul Dixon and Craig Conway on the left side of the team, and scored his first goal for the club with a header against Hearts at Tynecastle in February. He scored again four games later in the 3-1 win over Aberdeen at Tannadice, again with a header. By the end of his first season Barry had made 27 appearances for the club.

He made his European dedut in the opening game of the 2011-12 season, playing in the away leg of the UEFA Cup tie against Slask Wroclaw in Poland, but as the season went on he found it hard to displace the in form Paul Dixon from the left back position. Barry was used more as a left sided attacking player, making a total of 13 appearances for the season, and scored his third goal for the Club in the 3-3 draw with St Johnstone at McDiarmid Park.