The new deal will see Archer remain at The 1st Central County Ground until at least the end of the 2019 season.
The 21 year-old former West Indies Under-19 bowler enjoyed a fine breakthrough season at Hove, culminating with him winning the Young Player of the Year Award in September at Sussex’s end of season presentation.
He made his first-class debut against the touring Pakistan side in July, taking match figures of 5 for 73, and quickly went on to make his bow in all three competitive formats.
He claimed figures of 5 for 42 against Somerset in front of the Sky cameras in the Royal London One-Day Cup at Taunton, and his best haul in the Specsavers County Championship saw him take 4 for 31 at Grace Road against Leicestershire, which contributed to match figures of 7 for 62.
Archer also showed promise with the bat, hitting 73 against Essex at Colchester, sharing a partnership of 140 with Chris Jordan.
It was announced in early August that Archer had signed a first professional contract at Hove, but Sussex have moved quickly to secure the services of such an exciting talent for a prolonged period.
Archer said of his new deal, “I’m really happy to extend my contract. I can develop without any pressure and the aim is to continue to build on what I did last season.
“Last season was really pleasing because I thought all my opportunities had left me due to my previous injuries, so I was really grateful to be presented with this one at Sussex.
“My aim for next season is to take 70 wickets across all three formats, and if I can cement my place in the team then I think that can be a reality.”
Sussex’s Head Coach Mark Davis said, “I am delighted that Jofra has committed to a three-year contract with Sussex.
“He is a young player with immense talent with both bat and ball and has emerged as a very important cricketer for Sussex.
“He is still a young man learning his trade but the signs are clearly there that he will be an integral part of our future success.”