The deal keeps the World Cup hero at The 1st Central County Ground until at least the end of the 2022 season.
In an exclusive interview for the Sussex Cricket website, the 24-year-old said: “Sussex gave me my opportunity right at the beginning of my career, so I am very happy to commit long term to the club.
“I really do enjoy playing with everyone here at Sussex and it was really nice to come back down last year to play a few games with the lads.
“It’s the same club that I left it as and it’s nice to know nothing has changed. Sometimes people sit in my space in the dressing room now, but that’s fine!
“It most definitely still feels special to pull on the Sussex shirt.”
Sussex Cricket’s men’s head coach, Jason Gillespie added: “We’re delighted that Jofra will continue to be with us at Sussex.
“I’m really looking forward to having him play for us when his England commitments allows. He loves playing for Sussex – he’s like a kid in a candy store!
“We all love having him around, and seeing his improvements as a player has been great. Hopefully we can play a role in helping him continue to get better.”
Since his debut for Sussex in July 2016, Jofra has raced to 196 wickets in 97 appearances across all three formats. In first-class cricket for the county, he has taken 131 wickets in just 28 matches.
His outstanding performances for the county led to an England debut in May 2019. In just seven Test matches, Jofra already has 30 wickets, including three five-wicket hauls.
He was England’s leading wicket taker in their triumphant World Cup campaign last summer and bowled the super over that clinched Eoin Morgan’s side the trophy.