Steven Shingler will rejoin Scarlets from London Irish at the end of the season.
The fly-half crossed the Severn in 2011 but returns in the summer on a three-year-deal.
Shingler's brother, Wales flanker Aaron Shingler, has also agreed a new three-year contract with Scarlets.
Head coach Simon Easterby said: "It's important for our progression to have secured these two talented players from our region who will add real value to our squad going forward."
Steven Shingler said: "I have had some great experience from my time at London Irish, and it's been good for me to play in the intensity of the Premiership.
"During my time at London Irish I've been lucky to work with and learn from some great people like Mike Catt, who have pushed me forward and improved my game.
"I am very grateful to have this opportunity to come back to Wales, and back to what I consider my rugby home, playing for a region I feel so strongly about."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.