Backline duo re-sign with Tigers
Thompstone joined Tigers from London Irish in 2012 and has scored 18 tries in 76 appearances for the club.
Tigers Director of Rugby Richard Cockerill said: "We have a strong group of players in the back-three positions and Adam is a part of that.
"He has been in good form for us this season and can play an important part in the squad going forward."
An England Saxons cap, 28-year-old Thompstone started the first 10 games of this season in league and Europe for Tigers.
He said: "I'm enjoying my rugby and we've made a pretty decent start to the season in the league and in Europe.
"We have a very talented group of boys in the backline, we're playing some good rugby and I want to be part of that going forward and trying to contribute as much as I can."
Smith, already in his 11th season in the senior squad at Welford Road and enjoying a joint testimonial with club colleague Tom Croft, shared a piece of history in 2012/13 when he joined dad Ian 'Dosser' Smith as the first father and son in Tigers history to each pass 100 starts for the club.
Smith, a three-time Premiership title winner, has totalled 178 appearances for Tigers since his debut in the 2005/06 season and has scored 29 tries in club colours.
Cockerill said: "Matt has been a fantastic servant of the club and to have players who have such a strong link with Leicester, following their dad into the team, is very important here.
"He's been in outstanding form for us this season, his attitude to his work is first class and that is the kind of influence you want in the squad."
Smith, 30, said: "It means a lot to me to stay with my hometown team, it is where I have played all of my senior rugby.
"I feel like my rugby has really kicked on this season, we're playing some good stuff and I'm really enjoying it. Hopefully we're going in the right direction and everybody wants to be part of that."
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