 McGinn signed for Watford in January 2010, for an undisclosed fee.He made his first Watford appearance as a substitute against Newcastle United on 27 February 2010, and finished the season making two starts and seven sub appearances.The following season McGinn established himself as a first-team regular for Watford, missing just four games between August and the end of February, before damaging his knee ligaments in a 1–1 draw against Doncaster Rovers.