From April 2016, those in England and Wales will have to pay a 3% surcharge on each stamp duty band.
George Osborne said the new surcharge would raise £1bn extra for the Treasury by 2021.
Landlords reacted angrily to the change, saying it would "choke off" investment in rented properties.
The stamp duty surcharge will lift each band by 3%. That means that for properties worth between £125,000 and £250,000, where the stamp duty is 2%, buy-to-let landlords will pay 5%.
For the average buy-to-let purchase of £184,000, that means they will pay an extra £5,520 from April 2016.
Commercial property investors, with more than 15 properties, are expected to be exempt from the new charges.
Buy-to-let landlords will also be hit by a change to Capital Gains Tax (CGT) rules.
From April 2019, they will have to pay any CGT due within 30 days of selling a property, rather than waiting till the end of the tax year, as at present.
Landlords are already due to get a lower rate of tax relief on mortgage payments.
In his summer Budget, the chancellor said that landlords would only receive the basic rate of tax relief - 20% - on mortgage payments, a change being phased in from 2017.