The South Africans, aged between 19 and 32, had to submit a video of why they wanted to go to Mars and why they should be selected.
Mars One is a not-for-profit organisation, founded in the Netherlands, that aims to establish the first human settlement on the planet Mars by 2023.
The project would be on-going to provide primary funding for mankind's next giant leap, the website said.
The list of criteria for applicants was detailed.
"The astronauts must be intelligent, creative, psychologically stable and physically healthy," it said.
No coming back
Mars One would maintain 40 trained astronauts during the full duration of its missions.
The first group of four astronauts would set off to Mars in September 2022. The flight would take between seven and eight months.
They would be responsible for installing the connecting tubes between the individual capsules, configuring and activating the food production units, and assembling the remaining solar photovoltaic panels.
The astronauts would be joined by another four in June 2025.
One important factor was that once on the planet Mars, there would be no coming back.
"Once on Mars, there is no means to return to Earth. Mars is home," the website said.
Mars One co-founder Bas Lansdorp said: "Since we started Mars One in March 2011, we received support from scientists, engineers, businessmen, and women and aerospace companies from all over the world".
He said the announcement of their plan in May last year resulted in the engagement of the general public, and support from sponsors and investors.
"To see our mission evolve this way feels like my dream is becoming a reality," he said on the website.
Fellow co-founder Arno Wielders said working on Mars One was being a living part of the "incredible" undertaking.
"I believe mankind is destined to be a multi-planet species, to move beyond the confines of our home planet." – Sapa