Born in Salford, Greater Manchester, Riley started his professional career at Bolton Wanderers, regularly playing in the reserve side. A product of the youth system, he made his competitive debut in the League Cup tie at home to Macclesfield Town on 24 August 2011. Riley went on to make his Premier League debut at right-back in a 5–0 victory over Stoke City at the Reebok Stadium on 6 November 2011. He received a standing ovation by the Bolton fans when substituted late in the game. After starting the next game against West Brom, Riley suffered a hamstring injury; disrupting the start to his debut season. He returned in the FA Cup match against Macclesfield on 7 January 2012.
On 23 February, both Riley and Michael O'Halloran signed new three and a half year contracts, committing them to the club until the summer of 2015.