The 23 year-old winger, who passed through all levels of Swansea Schools, Swansea RFC and Wales age group rugby, left for Cardiff in 2003, signing a two-year contract. However, having been given limited first-team opportunities, as well as being laid low by injuries, the young star has been eager to return to his home region.
Ospreys' Rugby Manager, Derwyn Jones, says: "Johnny is one of Welsh rugby's hottest prospects and his skills are perfectly suited to the type of open and exciting rugby we play at The Ospreys. When you consider how his former teammates Jonathan Thomas and Richie Pugh have progressed with us in the last few years, it's the perfect place for him to fulfil his potential."
Ospreys' joint-MD, Mike Cuddy, adds: "Signing a player such as Johnny is great news for the region and demonstrates our commitment to developing young Welsh talent. We're extremely excited about working with him as he's a quality player with the potential to become an Ospreys regular and a full Welsh international.
"Furthermore, his arrival also raises the competition for places to new levels which is vital if we want to continue developing a squad of players to challenge the very best in Europe."
Vaughton said: "The Ospreys are quickly becoming one of the most feared sides in Europe and trying to break into a team packed with so many international stars will be a massive challenge. Nevertheless, I'm confident that I have the ability to succeed and can't wait to start working with the coaches and the rest of the team."
GB7s women left their England base to train in Wales this week. Olympic Games hopeful Rachael Burford gives WRU TV's Graeme Gillespie her thoughts on Welsh teammate Jasmine Joyce - a 'one touch wonder'
The GB7s women's squad is currently training at Wales' Centre of Excellence where assistant coach Richie Pugh tells WRU TV's Graeme Gillespie some 'tough calls' will have to be made when it comes to finalising the 12 spots for Rio's Olympic Games.
Wales U20's Billy McBryde is looking forward to starting his first game against New Zealand this afternoon in the World Rugby U20 Championship where his side are looking to gain revenge from last week's pool defeat to the Kiwis.