Parties and election observers see the election in Ekiti state as a test run for the 2023 presidential election.
Voters in Nigeria's Ekiti state have started casting their ballots to elect a new governor in what could be a bellwether for who wins next year's presidential election.
Although 16 parties are on Saturday's ballot paper, it is seen as a three-horse race between Biodun Oyebanji of the ruling APC, Bisi Kolawole of the People's Democratic Party and Segun Oni of the Social Democratic Party (SDP) to replace incumbent Kayode Fayemi of the APC.
According to Nigeria's Independent National Electoral Commission (INEC), the southwestern state has 988,923 registered voters of which almost 40 percent are aged 18 to 34.
The polls officially opened at 0730 GMT and are expected to close at 1330 GMT but voters who register before that time will be able to continue voting until later.
"Around 9:30am (0830 GMT)... accreditation & voting ongoing seamlessly," INEC tweeted about a polling station in the Emure district.
Civil society group Yiaga Africa said it was "observing the process across all local government areas".
Test run for 2023 election
Ekiti is among eight of Nigeria's 36 states where governorship elections are not being held at the same time as the rest of the country because of legal challenges to previous results.
Parties and election observers see the Ekiti vote as a test run for the 2023 presidential election.
On Wednesday, the candidates signed a peace accord, vowing to avoid violence and accept the outcome of the vote.
Police said they had deployed more than 17,000 personnel to ensure a trouble-free vote.