Van Poortvliet featured 19 times in the league when Tigers won the Premiership title in 2022, but was left out of the Grand Final side that beat Saracens.
While he missed out on the decider, he went on to earn his senior international debut for England a month later.
He has played 16 times for his country, with his latest appearances coming against South Africa and Japan in November.
Van Poortvliet had not featured for England for more than a year after an ankle injury forced him to miss last year’s World Cup.
Tigers head coach Michael Cheika described the playmaker as “a quality player and a quality person”.
“He knows what it means to play and win for Leicester,” Cheika continued.
“He is already at international level, and I believe there’s still lots of growth left in his game.”
Van Poortvliet is the fifth Tigers player to renew his contract with the club this week, following fellow England international Ollie Hassell-Collins, Ollie Chessum, Tonga centre Solomone Kata and Scotland prop Will Hurd.
