A product of Dundee United's youth development system, Watson made his first team debut in January 2007. His early career was disrupted by injury problems, and he spent periods on loan to Forfar Athletic and East Fife before establishing himself in the Dundee United team in 2010; he was a member of the squad that won the Scottish Cup that year. Watson established himself as a regular in the right back position, making his 100th league appearance in February 2014. He spent the latter part of the 2014–15 season on loan at Hibernian.