The 27-year-old will end his 10-year stay at the region to join Mike Ford’s side, having amassed 1059 points since graduating from the Scarlets academy.
Priestland joined the senior squad aged 18 in 2004 having played for Llandeilo RFC and Carmarthen Athletic. He represented Wales Under 19s and Under 20s before winning his first senior international cap during the 2011 Six Nations campaign in the 24-6 victory over Scotland. He was Wales’ first choice outside half at the 2011 Rugby World Cup and has 32 caps.
Since making his competitive debut in Scarlets colours in September 2007 the unassuming fly half has gone on to make 147 appearance for the region amassing a current total of 1059 points – just six points away from breaking Stephen Jones’ regional record and becoming the highest scoring Scarlet in regional history.
Priestland said: “I have thoroughly enjoyed my time here at the Scarlets; there have been some great highs and some heartfelt lows.
“It’s a huge privilege to have played with some of the players I have during my time here with the Scarlets.
“I have been lucky to have been involved in some fantastic fixtures and career highlights here at the Scarlets would have to include representing the region in the Heineken Cup over the years.
“The Scarlets has been my home for a number of years and all that I’ve known as a club as a senior professional player. I will certainly miss the place and will be leaving some great friends behind but there’s a long way to go this season. I just enjoy playing for this team. It’s my home region and every time I pull on the shirt it’s an honour.
“I will be fully committed to helping the team achieve the ambitions we have set ourselves at the start of the season. Hopefully it can keep on improving for me personally and as team for the rest of the season.”