McLaren confirms ‘multi-year’ deal for Button
The "multi-year deal" was confirmed in a media statement, at the end of a salary standoff with the 29-year-old Briton's title-winning team of 2009, Brawn/Mercedes.
"I want to make clear that Jenson's decision to join us was in no way motivated by money," said McLaren team boss Martin Whitmarsh.
"We'll be paying him no more than he could be getting elsewhere", he added.
McLaren said 2010 will be the first time in F1 history that a team has housed the sport's two most recent world champions, and the first time since 1968 that two British title winners are paired together.
Button said he made the "difficult" decision because he wanted a "fresh challenge".
"That's why I've decided to join McLaren," said the Briton, who will wear the number 1 on his MP4-25, while Hamilton's sister car is to bear the number 2.