Gudni Johannesson has spent most of his career commenting on Icelandic politics. Gudni Johannesson is expected to replace Olafur Ragnar Grímsson, who has held the office since 1996. Some 10% of Iceland's population is thought to be in France watching the country's footballers at Euro 2016.
The Icelandic consulate in France is flying ballot papers to the team hotel in Annecy so that the players can vote. However there are no such arrangements for Icelandic fans in France and that could mean a voter turnout of under 65%, low for the Nordic nation, local reports say. The presidency is a largely ceremonial post.
The election comes amid disenchantment with the political elite, some of whom were alleged to hold offshore accounts in the Panama Papers investigation into tax evasion. The scandal forced the resignation of Prime Minister Sigmundur Gunnlaugsson.
Mr Johannesson, 47, is an expert on political history, diplomacy and the constitution, and has not said which political party he supports. He says he is an ordinary father who likes to read, jog and play football and has also translated four books by US horror writer Stephen King.