McGinn, 24, spent last season on loan at League One side Brentford and has now signed a two-year deal with the Dons.
The former Derry City star also revealed he is looking forward to working under Craig Brown at Pittodrie.
"Aberdeen is a massive club and I'm really looking forward to be back playing in Scotland," he said.
"I thoroughly enjoyed my time at Brentford last season and, playing week in week out has, I believe, made me a better player.
"Craig Brown has big plans for the club and I definitely want to be a part of that."
The adidas Nitrocharge is the most talked about new cleat in years. It was released on May 15 and will take your pitch by storm.
The new PUMA evoSPEED 1.2 FG. A great new soccer cleat with classic look and first time for PUMA to be on the cleat.
Borussia Dortmund hears Wembley Calling and are headed to London for the Champions League final.
One of the top soccer cleats for control the Nike CTR360 will not let you down on the field in tight spaces.
Ajax has released their away soccer jersey for the 2013/14 season. Get in the Gear.
The Liverpool 2013/14 soccer jersey is available for pre-order. The Reds are eager to compete for silver next season.
Bayern Munich are kings of Germany and hope to be crowned kings of Europe at Wembley later this month!
adidas has added some color to the Predator line with this new colorway. Released on May 17. Be the first to own a pair.
The Juventus jersey for the 2013/14 was released earlier this week. Be the first to wear the colors of the Old Lady.
Chelsea won the Europa League on Wednesday. The Blues defeated Benfica 2-1 on injury time goal from Ivanovic.