She reached the final four times with her former side, winning in 2023, and is the competition’s second-highest run-scorer of all time.
All three play for Surrey, who hold a 51% ownership stake in MI London, where Curran is also the T20 skipper.
“This is a real statement of intent from our playing teams,” said MI London chair Oli Slipper.
“In Sam and Will, we have signed two of the best English white-ball cricketers there are.
“Danni is a fan favourite in south London with her performances for Surrey and England and has already tasted success at the Kia Oval.
“She’s been prolific in The Hundred and is one of the most exciting players in the game.”
The 2026 season is the MI London’s first since Reliance Industries Limited bought a 49% share of the franchise.
The Invincibles have won the men’s competition for the past three years, but their squad was broken up following the introduction of an auction format this season.
England internationals Sam Billings, who captained the side, Tom Curran, Gus Atkinson, Saqib Mahmood and Jordan Cox – all of whom have played exclusively for the Invincibles – were among the players not retained.
Teams were limited to four signings in the pre-auction window, but could re-sign former players at the event.
