Since leaving Parliament in 2017, Mr Osborne has also been appointed editor of the Evening Standard and adviser to Blackrock.
According to the Financial Times, Mr Osborne has been appointed as an adviser to San Francisco-based 9yards Capital.
Since leaving parliament in April 2017, Mr Osborne has also been appointed editor of the Evening Standard newspaper, become an adviser to the world's largest fund manager BlackRock, and chaired the Northern Powerhouse Partnership.
Mr Osborne is also adviser to Exor, the listed holding company of the Agnelli family, one of the richest in Italy. Companies owned by the £10.5bn family investment business include Fiat and Ferrari - and even Juventus football club.
He also holds a string of academic posts at Stanford Business School and the Hoover Institution.
Mr Osborne's brother, Theo, is founding partner of 9yards Capital, which has offices in London, New York and San Francisco.
On its website, the firm says it invests in "ambitious entrepreneurs, building global companies" and that it has "deep experience in financial services, venture capital and government".
The former chancellor's Silicon Valley role follows ex-deputy prime minister Nick Clegg's recent move to Facebook to be the social media giant's new head of global affairs and communications.