Rotherham United have landed their third former Sheffield Wednesday player of the summer on the day the FA confirmed defender Kirk Broadfoot has been banned for 10 matches.
Scottish forward Maguire joins other ex-Owls Joe Mattock and Lewis Buxton at the Millers, becoming boss Steve Evans’ 11th pre-season signing.
The 26-year-old, who scored 18 goals in 59 league starts for Wednesday, was allowed to leave Hillsborough at the end of last season.
Evans said: “This young man is a player I have admired since his days at Aberdeen. He was a lad that was on my targeted list of players at the end of last season.”
Fellow Championship clubs Bolton Wanderers and Blackburn Rovers were also interested in Maguire.
Meanwhile the FA revealed that Broadfoot will serve a 10-game suspension after an altercation with Wigan forward James McClean when the two clubs met at AESSEAL New York Stadium last March.
A statement said: “Following an Independent Regulatory Commission hearing, Rotherham United’s Kirk Broadfoot will serve an immediate 10-match suspension after a misconduct charge against him was found proven.
“The charge was that during a league fixture between Rotherham and Wigan Athletic on March 14 2015 Broadfoot used abusive and/or insulting words towards a member of the opposition, in breach of FA Rule E3(1).
“It was further alleged that the breach was an “Aggravated Breach” as defined by Rule E3(2).”
Broadfoot was also fined £7,500 and ordered to complete an education programme.