No financial details were given for a deal that will be presented formally at next month’s Singapore Grand Prix.
However Williams chairman Adam Parr, whose own team are losing bailed-out Royal Bank of Scotland as a major sponsor at the end of the year, said the real importance of the deal was the message it sent.
“This is a very significant announcement, regardless of the size of the sponsorship,” he said.
Parr added: “The fact that another major bank is looking to Formula One as its primary global marketing platform is very positive.”
UBS said it would use its sponsorship both for brand building in key regions and for hospitality for its “ultra-high net-worth clients”.