Ahead of the gathering, No 10 said Mr Johnson would announce a package of 18 investment deals, supporting growth in sectors such as wind and hydrogen energy, sustainable homes and carbon capture and storage.
At the same time the Department for International Trade is launching a new online investment atlas, highlighting 53 potential strategic investment opportunities across the UK.
The world’s top investors have seen the massive potential in the UK for growth and innovation in the industries of the future
Prime Minister Boris Johnson
Mr Johnson said the new investment would help power the UK’s economic recovery, driving the Government’s “levelling up” agenda.
“The world’s top investors have seen the massive potential in the UK for growth and innovation in the industries of the future,” he said.
“This is just the start. We will see new partnerships for green growth forged at today’s Global Investment Summit, as we look ahead to Cop26 and beyond.”
Following an opening address, Mr Johnson will sit down with Mr Gates, who is advocating technological solutions to tackle the climate crisis.
Downing Street said the Queen and other senior royals will host a reception at Windsor for the delegates, which Mr Johnson and Chancellor Rishi Sunak are also expected to attend.
Ahead of the summit, the Prime Minister and Foreign Secretary Liz Truss were hosting about 20 business leaders at a dinner in No 10 on Monday.
The Prime Minister’s official spokesman said it was being catered by Clare Smyth, the first woman chef in the UK to get three Michelin stars, with a menu “showcasing the best of British produce”.
Canapes of jellied eels, chicken liver parfait, and pumpkin and white truffle gougere were being served before a starter of potato and roe.
Venison from the Rhug Estate near Corwen in Denbighshire, prepared with a 16-year-old Lagavulin whisky, is followed by a dessert of lemon and pear meringue.
Mr Sunak will host a separate dinner in the City for about 300 business and industry figures.