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."
Ebbw Vale captain Damien Hudd picked up the biggest accolade of the night at the 11th Principality Premiership Awards Evening held at Principality Stadium, after leading his side to the title for the first time.
Wales assistant coach Robin McBryde is predicting a tough battle against England on Sunday despite the fact they may not be considered to be at full strength. Players will be out to impress Eddie Jones which makes England a dangerous proposition, he says.
Wales U20 captain Tom Phillips and performance psychologist Dr Rich Neil explain why spending three days at Monmouth RFC has further strengthened the togetherness of the squad ahead of the #WorldRugbyU20s
Alongside Scarlets flanker James Davies and Cardiff Blues centre Cory Allen, three Wales Sevens core players have made the extended training squad for GB Sevens. Wales Head coach Gareth Williams tells WRU TV's Graeme Gillespie why Luke Treharne, Sam Cross and Luke Morgan earned selection in the initial training squad for Rio.
Wales Sevens head coach Gareth Williams tells WRU TV's Graeme Gillespie he has had to overcome a number of injuries before naming a competitive squad for this weekend's penultimate round of the World Series in Paris.