Another candidate, 75-year-old former insurance executive Tan Kin Lian, was supported by several opposition leaders, but received only 13.88 percent of the vote.
“The presidential election is increasingly being treated as a general election,” said Mustapha Izzuddin, a Singapore political analyst at consultancy solaris strategies.
Voting is mandatory for Singapore’s more than 2.7 million eligible citizens.
According to the Department of Elections, as of 5:00 pm local time, more than 2.3 million Singaporeans, or about 85 percent of eligible voters, had voted.
The long but orderly queues at polling stations are absent from the noisy atmosphere that can accompany elections in other countries, with supporters shouting slogans or distributing leaflets to lobby for votes at the last minute.
Izzuddeen said that an increase in protest voting was expected, but Shanmugaratnam won overwhelmingly, despite what experts had said about a change of opinion about the ruling party.
The PAP suffered its worst ever election performance in 2020, but retained a majority of more than two-thirds.
Singapore requires presidential candidates to either serve as a senior civil servant or chief executive of a company with a shareholder equity of at least 500 million Singapore dollars ($370 million).