Ms Tsai Ing-wen's commanding victory brings to power her Democratic Progressive Party , which espouses Taiwan's formal independence from China, a red line for Beijing, which claims the island as its territory.
Making her the island's first female president, the 59-year-old former law professor immediately called for unity between Taiwan's political parties and repeated a campaign pledge to maintain the status quo and avoid surprises in relations with mainland China.
Ms.Tsai then launched into a robust defense of Taiwan's democracy, which has become a source of pride for Taiwanese and stands in contrast to China's one-party rule.
"Our democratic system, national identity and international space must be fully respected," Ms Tsai told a news conference at her campaign headquarters, as tens of thousands of supporters rallied outside in celebration. "Any suppression [of those] will harm the stability of relations" between China and Taiwan, she said.
While expected, the election result is a blow to the Chinese government, which seeks reunification with Taiwan and had forged a good working relationship with Taipei under departing president Ma Ying-jeou, a politician from the long-ruling Kuomintang or Nationalist Party. The result could also complicate Beijing's ties with Washington, which is obliged by U.S. law to help Taiwan defend itself.
During the campaign, Ms. Tsai, spoke to concerns among many Taiwanese about Beijing's rising influence during Mr. Ma's eight years in office and the effect China's economic heft was having in enriching a Taiwanese business elite, while drawing away jobs and investment from the island's economy.
Her ability to tap into those concerns proved decisive in the election, analysts said. "A Taiwan identity won," said Yen Chen-shen of the Institute of International Relations at Taiwan's National Chengchi University. "There is a generation of pro-independence people," he said, referring to young voters who rallied behind Ms Tsai.
Ms Tsai may also have gotten a boost from an outpouring of sympathy for a 16-year-old Taiwanese singer in a South Korean pop group who was excoriated by the Chinese on social media after she was seen waving a Taiwan flag in an online broadcast. The singer then issued an apology, in an apparent concession to the size of the mainland market, that angered many young Taiwanese.