Hugo Martinez from the left-wing Farabundo Marti National Liberation Front (FMLN); businessman Carlos Calleja from the right-wing Nationalist Republican Alliance (ARENA); former mayor of the country's capital, Nayib Bukele from the conservative Grand Alliance for National Unity (GANA); and Josue Alvarado from the centrist Vamos party are running for presidency.
Incumbent President Salvador Sanchez Ceren cannot run for a second consecutive term under the country's legislation.
Around 1,600 polling stations will be open from 7 a.m. to 5 p.m. local time (from 13:00 to 23:00 GMT). Over 5.2 millions citizens have registered to vote. Security measures will be enhanced, with the country's police, Armed Forces, and prosecution being in charge of it.
To win in the first round, a candidate must secure over 50 percent of the vote. Otherwise, a run-off will be held on 10 March, with two top candidates facing each other. In El Salvador, the president is elected for a five-year period.
Bukele is reportedly an active social media user who wants to modernize the local government, introduce infrastructure projects and push reforms to tackle country's economic issues.
Bukele has studied law at Jose Simeon Canas Central American University but reportedly left before getting a degree.
El Salvador's last six presidents have come from either ARENA or FMLN parties.