White, 32, only made his debut in 2020 but has built a solid record, particularly in red-ball cricket, where he took 114 wickets (25.18).
“I am incredibly honored and very excited to begin this new chapter with Yorkshire,” White said. “Headingley is a special place to play and having had conversations with the manager and club leaders, I look forward to continuing to develop my game and play my part in achieving success for Yorkshire.”
Yorkshire finished second in Division Two last season, securing their return to the top flight for the first time since 2022.
Gavin Hamilton, Yorkshire’s general manager of cricket, said: “We are delighted that Jack has committed his future to Yorkshire. He is a brilliant addition to the team, offering another dimension to our bowling attack.
“He is someone who works hard and came to professional football at a later stage in his development. He is the type of player and person who will continue to contribute to our dressing room, and we look forward to working with him at the club.”
Northamptonshire said they were “disappointed” to lose White, who was under contract until the end of the 2025 season.
“While it is a real shame that Jack has decided to move elsewhere, we all want to thank him for his efforts in the Northamptonshire shirt and wish him the best for the future,” added chief executive Ray Payne.