is a former professional football player and coach.

Born in Slough to Irish parents, McDermott joined Arsenal as an apprentice in 1977 and went on to play for Fulham, IFK Norrköping, Oxford United, Huddersfield Town, Cardiff City, Exeter City and Yeovil Town in a 14-year playing career during the 1980s and 1990s. At IFK Norrköping he was named Sweden's Player of the Year in 1984. He finished his playing career at Slough Town in 1995. The following season, he became manager of Slough Town where he had a very successful few years in the Conference.

Following the sacking of Brendan Rodgers, McDermott was appointed manager of Reading. In his first season as manager of Reading he led them into the quarter-finals of the FA Cup for the first time in 83 years, a run that included knocking out Liverpool at Anfield. The following season, he repeated the feat, this time with an away win over Liverpool's city rivals Everton. McDermott led Reading to a Championship playoff final, where they lost to Swansea City; the following season Reading were promoted to the Premier League after winning the Championship. On 11 March 2013, McDermott was sacked with the club in 19th place. McDermott made a swift return to management, replacing Neil Warnock at Leeds United. He left the post by mutual consent on 27 May 2014.

After a second stint as Reading manager, McDermott has worked as a scout for Arsenal and then joined Hibernian as their director of football in May 2023.