The former Ross County and Watford midfielder has joined the Latics on a bosman style free transfer from Cardiff City where he made twenty Premier League appearances last season.
Latics manager Uwe Rosler told the club's official website that he was pleased with the addition of Cowie who will help fill the void left by the departures of Jordi Gomez, Jack Collison, and Josh McEahran.
He said: "After we lost Jordi Gomez, Jack Collison, Josh McEachran, added to the longer-term injuries we’ve had with Ben and Chris, I wanted to bring in an energetic player with experience who knows all about getting out of this league.
"Don also played over 20 games last season in the Premier League; he’s 31 but he’s an extremely professional person and I’ve known about him for quite some time.
"From his training regime to the way he lives and breathes football he has the attributes to allow him to play football until his late 30’s.
"I think he knows the position, he has the ability to play a high-pressing game and an attacking forward game and I think he will add experience, reliability, a technical ability where all our players have to be so I look forward to working with him.
"He was a bosman player, he suits our Championship wage structure and he will give us alternatives in midfield."
Cowie joins a growing list of summer additions at the DW Stadium with fellow new arrivals Andrew Taylor, Aaron Taylor-Sinclair, James Tavernier and Oriol Reira.
Speaking about joining the Latics, Cowie told the Wigan Evening Post: "As soon as James McArthur found out I might be signing he was on the phone nearly every day to me, he spoke really highly of the club.
“You know what Jamesy is like he’s a great character, a hyperactive guy and it’s people like him who are great to work with on a daily basis in football.
“I know quite a few of the Scottish boys as well, and I know Leon Barnett and Andrew Taylor from my time at Cardiff, so it’s great to come into a squad with some familiar faces.”