Born in Gateshead, Owers began his career with Sunderland, making his debut in 1986 and playing in the 1992 FA Cup Final, in which Sunderland lost to Liverpool. In December 1994 Owers moved to Bristol City for a fee of £250,000, and he spent four years there, before moving to Sam Allardyce's Notts County in the summer of 1998. In 2000 Owers signed a new two-year deal with Notts County. He was released by Notts County at the end of the 2001-02 season and was signed by Nigel Spink, the manager of Forest Green Rovers in August 2002.
Owers became player-coach at Bath City in October 2003. He was appointed as Bath's new manager the following month, and led them to sixth place in the Southern League Premier Division in 2005-2006, missing out on the play-offs on goal difference.
Owers replaced Alan Lewer as manager of Forest Green Rovers in May 2005 after they had been relegated from the Conference National. However, they got a surprise reprieve as Northwich Victoria's ground failed to meet division rules, meaning they were relegated with Forest Green taking their place.
In his first season in charge of Forest Green, where he managed the club's first ever full-time professional squad, he led the team to 19th place in the Conference avoiding relegation on the last day of the season with a 2-0 victory over Stevenage Borough. However, after a disappointing start to the 2006-07 season, he left the club alongside assistant manager Shaun Taylor in August 2006.
On 11 November 2009 Aldershot Town Manager Kevin Dillon, confirmed that Owers was to be his new Assistant Manager at Aldershot Town.Under Dillon and Owers Shots finished in their highest ever league position ( 6th ) before losing to Rotherham over a two legged play off semi final.
In June 2011 Owers was appointed as a scout at former club Bristol City under manager Keith Millen.Promoted to first team coach after the arrival of Derek Mcinnes.
In June 2012 Owers joined the coaching staff at Plymouth Argyle primarily to work with the youth team players under newly appointed Academy Manager Kevin Hodges. In January 2013 Owers was promoted from Argyle's youth set-up to begin working with the first team by newly appointed manager John Sheridan.
In April 2014 he left Plymouth Argyle, with his role being taken up duly by Sean McCarthy and player Paul Wotton. In March 2015, he was confirmed Head of Recruitment at SPFL Premiership side Motherwell. However, only three months later in June 2015 he was named as assistant manager to Malcolm Crosby at National League club Gateshead but left the club in November 2015 following the sacking of Crosby. On 4 February 2016, he returned to Twerton Park for a second spell as manager of Bath City.
On 13th September 2017 it was announced that Owers has left his position at Bath City to accept the role of Torquay United head coach.
Gary works as Head English based Scout for Scottish Premiership team Partick Thistle, setting assignments for their network of 4 scouts watching games in the English lower leagues. Thistle have signed Adam Barton from Portsmouth, the 1st transfer fee paid by Thistle in many years, & Ade Azeez from AFC Wimbledon on the back of this scouting network.