New York Mayor Michael Bloomberg is to address the Conservative Party conference on its opening night later this month.
The Tories said the billionaire businessman would talk about the challenges facing the world economy when delegates gather at Blackpool's Winter Gardens on Sunday, September 30.
Mr Bloomberg said: "The ties between the United Kingdom and the United States run deep, and obviously many British companies do business here in New York City and vice versa - our economies are intertwined.
"I look forward to returning to the UK and I'm happy to have been invited to Blackpool to speak on economic matters and policy to the Conservative Party conference."
Mr Bloomberg, a one-time Democrat who switched allegiance to the Republicans, severed his ties with the latter in June.
He subsequently denied harbouring any ambitions to run as an independent in next year's US presidential elections.
Tory leader David Cameron said: "I am delighted that Mayor Bloomberg will join us in Blackpool.
"He is one of America's most inspirational and effective leaders."
