Clad in face shields, election officials enforced safe distancing rules and took voters' temperatures as they entered polling booths, with the morning session mainly reserved for the elderly to prevent overcrowding.
Nevertheless, some voters were still concerned about the risk of infection, as community COVID-19 cases have been rising across the country in recent days.
"Generally, I just feel that perhaps, timing-wise, this could be held at a later point in time, especially during this period," said a 33-year-old voter.
In power since independence in 1965, the ruling People's Action Party (PAP) is expected to carry Prime Minister Lee Hsien Loong to another comfortable, and probably final victory.
A record 11 parties are contesting. Singapore is not the first country in Asia to hold elections during the pandemic - South Korea held parliamentary elections in April - but its mandatory ballot comes under strict conditions.