Fonseka will contest from the Colombo District under Democratic National Alliance (DNA) against ruling UPFA and former premier Ranil Wickremesinghe's UNF.
Somawansa Amarsinghe, the chief of Marxist JVP, said that the nomination papers of the 59-year-old Fonseka has been approved.
The nomination papers of the former army general were filed by DNA general secretary Vijitha Herath.
Fonseka will be represented by his wife Anoma during the election campaign.
"We will be campaigning across the country. North and East (of Sri Lanka) are important for us and we did well there during the Presidential elections," Amarsinghe said in a news agency report.
The former army chief was detained on charges of conspiring military coup after his defeat in the presidential election on Jan 26.