Richie Pugh left the Ospreys in 2007
Wales Sevens World Cup winner Richie Pugh has joined the Scarlets, along with centre Gareth Maule, flanker Damien Welch and wing Andrew Fenby.
The news marks a return to Wales for once-capped openside Pugh, 25, who left the Ospreys in October 2007.
Pugh played on loan for London Welsh before joining Exeter Chiefs, Maule joins from the Dragons, Welch from Cardiff RFC and Fenby from Newcastle.
But back row Nathan Thomas has left after three seasons with the Scarlets.
The west Wales region has also officially confirmed that New Zealand openside flanker Daniel Braid will not be joining the Scarlets after rupturing his Achilles tendon.
Last month Braid told Australian media outlets that he would not be coming to Wales and was considering other options in Australia.
Pugh, Maule and Welch arrive at Parc y Scarlets on two-year contracts, while Rhos-on-Sea product Fenby has a one-year deal.
Scarlets head coach Nigel Davies said: "I'm thrilled that these players have agreed to join us. They will strengthen our squad substantially in terms of the skills and balance they bring.
"We've been tracking them for considerable time and have researched them in detail.
"They all have huge potential and I'm confident that by bringing them into the Scarlets environment we can help them fulfil that promise.
"We're at a very important stage in our rebuilding and regeneration process at this region and the fact that we can recruit exciting Welsh talent should give everybody connected with the Scarlets great hope for the future."
The four new signings are in addition to other recruits Scotland wing Sean Lamont (Northampton Saints), prop Rhys Thomas (Dragons) and scrum-half Tavis Knoyle (Neath RFC).