Born in Neath, the young developing outside half who has played the majority of his rugby in recent seasons with Scarlets' Premiership partner club Llanelli RFC, has progressed within the Scarlets development pathway having been secured into Scarlets rugby in 2010.
Between 2010 and 2012 he made 30 appearances for Llanelli RFC. He has represented Wales at U20 level. His first club was Ystradgynlais.His senior debut for the Scarlets came in the LV=Cup against Newport Gwent Dragons in February 2011.
Williams moves from a strong group of outside half talent at Parc y Scarlets with Wales first-choice international Rhys Priestland, new signing Steve Shingler - brother to Wales international Scarlet Aaron who moves from London Irish back home, plus Aled Thomas who has worked solidly for his region in the absence of the injured Priestland currently sidelined with an Achilles injury.
The Scarlets also have Dan Newton at 10, plus rising star Jordan Williams developing well in the number 10 and 15 jerseys - with an impressive performance and try this weekend against Scotland for the Wales U20 side which cut through the Scottish team with a resounding victory in Inverness.
Scarlets Head Coach Simon Easterby said: "Owen Williams has been on our development pathway for a number of years and is another example of a young player we have invested in and that has progressed well within our system - highlighted by his involvement with the senior squad this season.
"We had fully expected him to continue on that journey with us following the significant commitment this region has made in developing his rugby skills and experience to date.
"We have handed him some excellent opportunities recently this season which he has taken very well and which we believed showed our intent to develop him further as a Scarlets player.
"However, sometimes performances on the bigger stages bring with it additional attention from outside our group and he along with his agent have made his decision to move to England at this time at the end of his development contract with us.
"Of course, Owen goes with our very best wishes for the future and we wish him every success. He is still a young Welsh player with a lot to experience and prove and in making this decision we sincerely hope he gains from his time at a Premiership club."
Easterby said the Scarlets were comfortable with the depth building around the no10 jersey at Parc y Scarlets with a number of experienced, talented and ambitious outside halves secured within their ranks.
The Head Coach added that the Scarlets had offered Williams the option to discuss an extended senior contract with the West Wales region for next season and that the decision to move to Leicester Tigers had come suddenly and with no prior warning or discussion with the region.