Leading suffragist Millicent Fawcett is to become the first woman with a statue in Parliament Square.
The likeness of Ms Fawcett, who led the campaign for women's votes in 1866, will be unveiled yards from the statue of Winston Churchill and six other Prime Ministers.
It will form part of celebrations to mark the centenary of the Representation of the People Act 1918.
The act was introduced thanks to Ms Fawcett's campaigning and which first gave some women the right to vote, the Government said.
Nearly 85,000 people backed a petition calling for the statue.
Prime Minister Theresa May said: "The example Millicent Fawcett set during the struggle for equality continues to inspire the battle against the burning injustices of today.
"It is right and proper that she is honoured in Parliament Square alongside former leaders who changed our country.
"Her statue will stand as a reminder of how politics only has value if it works for everyone in society."
Chief Executive of the Fawcett Society Sam Smethers said:“We are delighted that Millicent Fawcett, the woman who led the constitutional campaign for votes for women, will finally be honoured.
“A statue of her in Parliament Square will be a fitting tribute. Her contribution was great but she has been overlooked and unrecognised until now. By honouring her we also honour the wider suffrage movement.
“The Fawcett Society will be using the centenary next year to tell that story in all its diversity.”
Mr Khan, who referred to himself as a "proud feminist", said: "Today just 2.7 per cent of British statues are of named women – so we have a lot of ground to make up.
"The 1918 Representation of the People Act was a key milestone in the struggle for gender equality and it’s only right that we commemorate this significant anniversary with Parliament Square’s first statue of a woman."