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."
WRU Chief Executive Roger Lewis, Deputy Minister for Culture, Sport and Tourism Ken Skates and WRU Chairman Gareth Davies earlier this week launched a new competition in conjunction with the WRU unveiling its archive room.
Welsh players and management joined Deputy Minister for Sport Ken Skates at the Pierhead Building, Cardiff Bay earlier this week to reveal the Union's pioneering school-club hub initiative has been so successful the project will now almost double the scale of the original project.
The Scarlets, Newport Gwent Dragons, Cardiff Blues and the Ospreys look ahead to Judgement Day III which sees the Blues take on the Ospreys (2.30) and the Dragons tackle the Scarlets (4.45pm) at the Millennium Stadium tomorrow afternoon.
Ystradgynlais and Ynysddu played out a titanic struggle at Taffs Well in the SSE SWALEC Bowl semi-final. At the end of the game neither team could be separated after a 15-15 stalemate but Ystradgynlais go through on try count.
Blues strike first in JD III battle - Newport Gwent Dragons lock Andrew Coombs, WRU referee Dylan Llyr Jones and Cardiff Blues hooker Matthew Rees decide dressing room allocations for Judgement Day III
Wales Under 18 captain Calum Haggett has received a conditional offer to read Biomedical Science at St Anne's College, Oxford. WRU chairman Gareth Davies went to meet Calum and Coleg y Cymoedd Principal Judith Evans to wish him luck in his exams and pass on some of his personal experience.
Dodgy tattoos, carthorses, Avatar and soft chins are revealed by Wales Sevens players Tom Williams and Sam Cross as they profile the Wales Sevens squad taking part in Hong Kong this weekend in the latest round of the HSBC Sevens World Series.