The Airtricity Premier Division champions have completed the signing of the centre back ahead of the new season from Dublin-based outfit Bohemians
The 26-year-old centre back, who has had spells at St Patrick's Athletic and UCD, has agreed to join Ian Baraclough's side for the 2013 season.
Speaking to sligorovers.com, McMillan revealed that 'there is no better place to be' than with the league champions.
"It is brilliant to complete the move," he said. "There is a unique and enticing atmosphere to the club. When I visited Sligo last year, I looked at the facilities, the set-up and everyone I spoke to was extremely complimentary of Ian's coaching style and his coaching technique. I feel the brand of football will suit my game."
He added: "Sligo are the champions so there is no better place to be. It is different to Dublin clubs and I could have easily stayed at home with a team up here but I feel this is the best place for me.
"I move down this weekend and like all players that come here, the focus is very much on football. You train in the morning, you continue in the afternoon and everything is driven towards football. That was very appealing." said the defender.
Bit O' Red boss Ian Baraclough revealed that he was 'very pleased' to have secured the signature of the 26-year-old.
He said: "I'm very pleased to bring Evan to the football club. We have pursued Evan for two months, he is the type of player that we want to bring here.
"I think it is worth the wait. We had to be patient to bring in new players and we asked for people to be patient because you don’t just bring them in for the sake of it," added the Sligo boss.