Voting started at 7:00 a.m. local time and ended at 4:00 p.m. local time.
Election monitors said 15,760,867 voters, or some 70 percent of the total eligible voters, cast their votes throughout the country, Xinhua news agency reported.
President Maithripala Sirisena, Prime Minister Ranil Wickremesinghe and former President Mahinda Rajapakse were among those who voted early on Saturday.
Voting for the local government elections is the first conducted by the newly-established independent Election Commission as well as the police under the Independent Police Commission.
It is also the first island-wide poll to be held since the coalition government of President Sirisena and Prime Minister Wickremesinghe took office in August 2015. The poll is considered an important test of the government's reform agenda.
The government said the services of 65,758 police officers, 41,178 Special Task Force officers and 7,278 other officers were deployed for the local government elections.
Police said that till noon, 11 people had been arrested across the country for violating election laws such as putting up posters and filming ballot papers.
No election-related deaths had been reported.