Bowe, a Ravenhill favourite, has enjoyed his spell in Wales, but is looking forward to returning to Belfast.
The winger said: "Obviously, I have mixed emotions. I'm sad to be leaving a club and a region that I have been proud to call my home for the last three years and that has improved me immeasurably both as a rugby player and as a person.
"I am indebted to the staff, coaches, management, team-mates and fans of the Ospreys for welcoming me so warmly and making my time here so special.
"That said, I am also delighted to be returning to Ulster, the province I grew up wanting to play for and where my family live.
"David Humphreys was a mentor of mine in my early playing days and we have remained friends during my time at the Ospreys. His vision for Ulster is impressive, with Ulster-born players at the core of this vision.
"I hope to repay the IRFU and Ulster's faith in me by contributing to a team that is already delivering. The vibe at Ulster is undeniably positive.
"I've been training and playing with some of the Ulster boys during the Six Nations and there is a real energy and sense of anticipation as to what lies ahead for this Ulster team."
IRFU Chief Executive Philip Browne commented: "The policy for the IRFU will continue to have as many Irish qualified players playing here in Ireland to maintain both the competiveness of the provinces and to allow the players to be managed for the benefit of the Ireland team.
"I am delighted that Tommy has chosen to return to Ulster to play and it speaks volumes for both the system we have here in Ireland and the building momentum in Ulster that a player of his standing in the game has committed himself long term to his home province."
Ulster director of rugby David Humphreys added: "We are delighted to be in a position to finally confirm that Tommy will be playing his rugby with Ulster next season and I'd like to thank the IRFU for their assistance in bringing him home.
"The speculation around his return over the past number of weeks is testament to the level of regard that the Ulster Rugby public have for him and rightly so.
"Skillful, physical, and a proven finisher with a knack of being in the right place at the right time, there's no doubt that Tommy has consistently been one of European rugby's best players over the past few seasons and he'll bring a lot of experience and flair to our back-line."
Schooled at Royal School Armagh, Bowe began his professional career with Ulster, making a try-scoring debut for the province in the 2003/04 season.
His elevation to the senior Ulster team followed selection for the Ulster Schools team and also playing at full-back and winger for the Ireland Under-21 team in 2004, being part of the squad that reached the final of the IRB Under-21 World Championship, but was ruled out of the semi-final and final due to injury.
Bowe won his first senior cap for Ireland against the USA in the old Lansdowne Road the following season, scoring a try on his debut in November 2004.
He continued to play for Ulster for the following three seasons, amassing 91 appearances and scoring 34 tries. During that time, he was part of the Ulster side that won the 2004/05 Celtic League.
At the end of the 2007/08 season, he moved to the Ospreys club in Wales and continued to represent Ireland, being part of the Ireland team that won the Grand Slam in 2009 and he was also selected to tour South Africa with the British & Irish Lions, playing in six games including all three Test matches.
The 2010 season was a particularly good year for the Monaghan man, being named as the RBS Player of the Championship for the 2010 Six Nations as well as the IRUPA Player of the Year and the Guinness Rugby Writers of Ireland Player of the Year.
He was selected in the Ireland squad for the 2011 Rugby World Cup, scoring two tries against the USA in New Plymouth and has continued that form by scoring five tries so far in the 2012 Six Nations.
Tommy Bowe Career Details:
Born: February 22, 1984
Ireland Career -
Debut: v USA, November 20, 2004
Points: 120 (24 tries)
Ulster Career -
Debut: v Connacht, April 16, 2004
Points: 170 (34 tries)
Ospreys Career -
Debut: v Connacht September 5, 2008
Points: 180 (36 tries)
British & Irish Lions Career -
Debut: v Royal XV, May 30, 2009
Points: 20 (4 Tries)