Independent candidate Kais Saied and imprisoned media proprietor Nabil Karoui advanced to the run-off after securing the most vote's in Tunisia's presidential election on September 15.
The official announcement was made by the country's electoral commission on Tuesday in the capital Tunis.
Law professor Saied won 18.4 per cent of the vote, while Karoui, owner of Nessma TV, obtained 15.6 per cent.
Karoui is currently under investigation for money laundering and has been in pre-trial detention since August 23. He denies all wrongdoing and believes the charges are politically motivated.