The future of Taiwan’s democracy is on the line as the self-ruled island’s 19 million voters decide on whether to give independence-leaning President Tsai Ing-wen a second term.
Voting began at 8am local time (12am UK time) on Saturday and wraps up at 4pm.
The vote count will begin soon after, with results expected later in the evening.
Miss Tsai and her main challenger, Han Kuo-yu of the Nationalist Party, both voted shortly after polls opened. Mr Han voted in Kaohsiung, the city in southern Taiwan where he is mayor.
“I hope every citizen can come out and vote,” Miss Tsai said after casting her vote in Taipei, the capital. “You should exercise your rights to make democracy stronger in Taiwan.”
For many in Taiwan, months of protests in Hong Kong have cast in stark relief the contrast between their democratically governed island and authoritarian, communist-ruled mainland China.
Miss Tsai said at a final campaign rally on Friday night that the election was a chance to protect Taiwan’s democracy.
“Let us tell the world with our own votes that Taiwanese are determined to defend sovereignty, determined to guard democracy and determined to persist in reforms,” she said.
The Nationalist Party’s Mr Han has said Taiwan should be more open to negotiations with China, in contrast to Miss Tsai, who has dismissed Beijing’s overtures.
At his last rally, attended by hundreds of thousands of people in the southern port city of Kaohsiung, he focused on practical issues such as improving education and the economy.
“I want to attract massive investments. I want products to be exported non-stop,” he said.
China and Taiwan separated during civil war in 1949, but Beijing still claims sovereignty over the island and occasionally threatens to use force to seize control if necessary.
The Hong Kong protests have undermined Taiwan support for the “one-country, two-systems” approach Beijing has championed for governing both that former British colony and Taiwan.
Fears of Chinese interference in Taiwan’s politics and an uptick in the economy have helped Miss Tsai regain an edge after a dire electoral setback for her Democratic Progressive Party (DPP) 14 months ago.
“The reason why I vote for her is for upholding the value of Taiwan’s freedom and democracy and that should not be affected by the other side of the strait (China),” Lucy Ting, a college student, said at Miss Tsai’s rally on Friday.
The Nationalists have struggled to find candidates who can fire up their pro-China supporters and win over young Taiwanese who increasingly favour the DPP.
A win by Miss Tsai is anticipated to draw more diplomatic, economic and military pressure from Beijing on the island, in a continuation of President Xi Jinping’s campaign to compel her administration to endorse its insistence that Taiwan is a part of China.
Miss Tsai has refused to do so, maintaining Beijing has no claim over Taiwan, although her government has repeatedly called for the reopening of talks between the sides without preconditions.
Since its transition to full democracy beginning in the 1980s, Taiwan has increasingly asserted its independent identity from China even though it is not recognised by the United Nations or any major nation.
The island of more than 23 million people exercises all the roles of a sovereign nation, issuing its own passports, maintaining its own military and legal system and serving as a crucial hub in the global high-tech supply chain.
If re-elected, Miss Tsai will face challenges in trying to reform the government and economy and push through unpopular cuts in generous civil service pensions.