Maggie Keswick Jencks and Mary Slessor will be the first women commemorated in the Hall of Heroes at the National Wallace Monument in Stirling.
The Maggie's Centres co-founder and the Scottish missionary were chosen by a public vote, which originally intended to only pick one winner.
The monument was opened in 1869 and attracts over 100,000 visitors a year.
The first busts, of Robert Burns and Robert the Bruce, were installed in 1886.
The new sculptures of Maggie Keswick Jencks and Mary Slessor will join the gallery alongside the existing sixteen busts of famous men from Scotland's history.
A shortlist of 14 women had been drawn up with the aim of selecting a single heroine to be added to the Hall of Heroes.
The selection panel said the two women "emerged clearly" as frontrunners, resulting in the "momentous decision" for both to be commemorated.
Maggie Keswick Jencks designed the blueprint for the Maggie's Centres, which offer practical, emotional and social support for people diagnosed with cancer, their families and friends.
Aberdeen-born Mary Slessor, who was raised in Dundee, was a missionary in Calabar, Nigeria, living with tribes and learning their language, before becoming the first ever female magistrate in the British Empire.
Zillah Jamieson of Stirling District Tourism, said: "This has been an incredible campaign, one which has ignited passions and has stimulated an amazing response.
"The level of enthusiasm for women to be given recognition has been truly inspirational.
"The challenge for us as a self-funding charity has been to raise the funds required to embark on this project, and to now introduce these women into the Hall of Heroes."