It is the first novel written in Mandarin Chinese to win the prestigious prize for fiction translated into English.
The book follows a Japanese novelist with a "monstrous appetite" as she goes on a culinary tour through 1930s Japan-occupied Taiwan, with the help from a local interpreter.
The "captivating" novel, which was originally published in Mandarin Chinese in 2020 before being published in English in March, explores themes of colonialism, power, class and love.
British novelist Natasha Brown, who chaired the judging panel, called it a "captivating, wryly sophisticated" book that plays with themes of language and power and offers the reader surprises along the way.
The novel purports to be a travel memoir by a Japanese novelist on a culinary tour of Taiwan and charts the - fictional - writer's complex relationship with her local interpreter.
Brown said the book explores class and colonialism, asking: "Can love overcome a power imbalance?"
She said it "pulls off an incredible double act: It succeeds both as a romance and as an incisive postcolonial novel".
Yáng, who writes fiction, essays, manga and video game scripts, has said she "wanted to untangle the complex circumstances" of Taiwan's time as a Japanese colony.
"Research for the novel's central themes of travel and food changed my life in two obvious ways: my savings went down; my weight went up," she told the Booker Prizes website.
Published in its original language in 2020, Taiwan Travelogue is the first of Yáng's books to be translated into English.
In the US, it won the National Book Award's translation category in 2024.
The judges praised the way Taiwanese-American translator King's translation adds another layer to a book that plays with ideas of communication across languages.
The book beat five other finalists to the prize, which recognises translated fiction from around the world published in the UK or Ireland.
The winning book was announced at a ceremony in London's Tate Modern on Tuesday with its stg50,000 ($A94,176) prize money divided equally between the author and the translator.
The International Booker was set up to boost the profile of fiction in other languages - which accounts for only a small share of books published in Britain - and to salute the under appreciated work of literary translators.
with PA
