Sisi, 68, can stand for a third term due to constitutional amendments in 2019 that also extended the length of presidential terms to six years from four, opening the way for him to stay in office until at least 2030.
Election results are expected to be announced on December 18 and, in the event of a run-off round, final results should be announced on January 16 at the latest, the election authority said.
Although Sisi has not formally announced his candidacy, pro-government parties have started a campaign including billboards around Cairo backing his re-election.
Sisi was declared winner of both the 2014 and 2018 elections with 97 per cent of the vote.
In 2018 he faced just one opponent, himself an ardent Sisi supporter, after the main challenger was arrested and other hopefuls pulled out citing intimidation.
Four other candidates have expressed an intention to run this time.
Most prominent is former member of parliament Ahmed Eltantawy, who says security services have arrested some of his associates and blocked him from holding election events.
Officials have not responded to his allegations.
Former army chief Sisi became president in 2014, the year after he led the overthrow of democratically elected Mohamed Mursi of the Muslim Brotherhood following protests against Mursi's rule.
Analysts say Sisi retains the backing of the security services, most importantly the army, which has become more powerful and expanded its economic influence.
Sisi's presidency has been marked by a crackdown on dissent across the political spectrum.
Sisi and his backers said the measures were needed to bring stability after the 2011 ousting of former president Hosni Mubarak in the "Arab Spring" uprisings and pave the way for economic development.
Activists say tens of thousands have been jailed since 2013, often without fair trials, and that the crackdown has continued despite the pardoning of some high-profile prisoners and the launch of a country-wide political dialogue.
