On 22 May 2012, Maguire was transfer-listed by Derby. Sheffield Wednesday, newly promoted to the Championship, had two bids rejected to buy Maguire in May 2012 but on 21 June 2012, they announced that Maguire had joined them on a three-year deal. He made his Owls debut in the 4–2 League Cup win over Oldham Athletic on 13 August. However Maguire had to wait until 16 March 2013 for another league appearance in the 0–2 defeat against Cardiff City. When right midfielder Michail Antonio was brought down and injured, Maguire came on as substitute. Maguire made his second league appearance, again as substitute, in the 2–1 victory against South Yorkshire rivals Barnsley. Maguire made a fourth appearance for the Owls in a 3–2 victory over Blackburn Rovers, replacing Jermaine Johnson in the 84th minute. Maguire came on as substitute and grabbed a late six-yard goal in the 92nd minute in his first goal for the Owls against Millwall in 2–1 away victory on 9 April 2013.