England back-rower Willis extends Toulouse contract until 2026
The 26-year-old arrived at the Top 14 outfit in November after former side Wasps went into administration.
His new deal will keep him at the record five-time Champions Cup winners until 2026, with two of those seasons optional.
"I have loved these past six months with Toulouse and I'm very happy and grateful to extend my contract here," Willis said in French on Toulouse's social media platforms.
"Thanks for your welcome and support since my arrival in Toulouse.
"I love being part of this squad," he added.
Willis was among a host of players to join French clubs after Wasps and Worcester's financial problems - his brother Tom signed for Bordeaux-Begles.
Jack Willis featured for his country in November as well as in this year's Six Nations thanks to an exception to England's rule about selecting players based outside the country.
He is set to continue to represent Steve Borthwick's side at this year's Rugby World Cup, starting in September.
"As it stands, anyone plays abroad isn't allowed to play (for England)," Willis said last weekend.
"After the World Cup is not for me to comment on that, really, it's up to them," he added.