Individuals and companies that are not tax resident in the UK will liable for the levy which could be as high as 3%, the prime minister announced as the Conservative party conference started.
Foreign buyers help drive up house prices and make homes less affordable for ordinary people, the party said.
Theresa May added: “For too many the dream of home ownership is too distant and the indignity of rough sleeping remains all too real.
“We’re committed to helping British residents get the right home for them.
“This higher stamp duty for non-residents will help to end rough sleeping for good.”
Britain open to immigration
Stamp duty is charged on homes worth more than £125,000 at a tiered rate, and anyone buying a second home pays an extra 3%.
Details of when the new tax will take effect have not been released.
Britain will always be “open to people coming here to live, work and build a life”, the Conservatives said.
Earlier this year, New Zealand banned foreign buyers, with some exceptions, from home ownership.
At its party conference Labour released plans for an extra tax on holiday homes, which would be used to fight homelessness.