Shadow chancellor John McDonnell will join US President Donald Trump and some of the world's leading business figures at the annual World Economic Forum meeting.
Mr McDonnell, a longstanding critic of capitalism, will use the event at the upmarket Swiss ski resort Davos to set out why it is "vital we rewrite the rules of the global economy".
A spokesman for the shadow chancellor said Mr McDonnell would use the meeting to set out Labour's "alternative economic approach".
Mr Trump is thought likely to use his appearance to promote his America First strategy at an event associated with the rise of globalisation.
Both Prime Minister Theresa May and Chancellor Philip Hammond attended last year's summit and the fact that Mr McDonnell has been invited will be seen as a sign that Jeremy Corbyn's Labour is being taken increasingly seriously internationally.
The shadow chancellor's spokesman said: "John McDonnell has accepted, and will use the opportunity to set out why it is vital we rewrite the rules of the global economy.
"He will further explain Labour's vision for an alternative economic approach to replace the current model of capitalism that has failed the many; and led to an unsustainable concentration of wealth and power in the hands of a few.
"In addition, he will raise many of the issues facing working people in our country, and across the world.
"The shadow chancellor will also call for greater international co-operation on the urgent threat posed by climate change, and raise the problem of growing inequality across the developed world, and the need for countries and corporations to work closer together to clamp down on tax avoidance and evasion."
The event takes place in Davos between January 23 and 26, with business leaders, politicians and representatives from non-government organisations among those attending.
Mr Trump would be the first sitting US president to attend the summit in person since Bill Clinton in 2000.