Seymour, 32, is fifth on the all-time list of the country’s try scorers and was part of the British & Irons Lions squad in New Zealand in 2017, finishing the tour as top try-scorer.
He has spent the last ten seasons with Glasgow Warriors and helped them win the Guinness Pro12 in 2015, beating Munster in the final in Belfast.
A prolific try-scorer, Seymour crossed the line on 48 occasions in his 150 appearances in Glasgow colours. His record at Test level was even more impressive, with 20 tries in his 55 starts for Scotland before he retired from international rugby after the 2019 World Cup.
He was born in Nashville, Tennessee, and moved to Belfast when he was young. He won youth caps for Ireland and played for Ulster before moving to Glasgow and qualified to pay for Scotland through his Glasgow-born mother, Sue.
He quickly became a firm favourite at Glasgow and only DTH van der Merwe has scored more tries for the club.
His appearances recently have been limited by injury and concussion and Seymour has decided to retire.
“Although my decision has been made for some time, the words seem almost impossible to write,” he told the club’s website.
“Firstly, to the club that made a home and wove me into its tapestry. Thank you for believing in me and for having faith when you had no reason to. This is my club, this is my home and I’ll never forget what it was to live and play here.
“To the fans that support this club so passionately, it was the greatest privilege to stand behind that badge and represent you in this beautiful game.
“To the physios, S&C and office staff I’ve been so fortunate to work with over my years, your help and presence in my career will never be forgotten. I can’t thank you enough and it was a pleasure to have dealt with you all.
“Lastly and most importantly to my wife Katy and my beautiful kids. You’ve been the backbone that held everything together. I wouldn’t have achieved and had this career without your love and support. The moments were made special because you were there to share them. I’m so proud to be your husband and father.”
Warriors coach Danny Wilson said: “Having made over 150 appearances for Glasgow in 10 years at the club, representing his country and playing for the British & Irish Lions, Tommy has achieved a huge amount in the game.
“He will be missed and his achievements within the game should be celebrated. He’s a well respected leader here at Glasgow and has done a lot for both club and country.
“He has been a fantastic servant to the club and we wish him all the best for the future.”
Al Kellock, the Warriors managing director and former captain, said: “I’ve known Tommy for almost 10 years - he’s an incredible rugby player but more importantly a great man.
“He has put a huge amount of himself into this club and has helped enormously on the journey we have gone through.”
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