To compile the list, Time Out surveyed more than 18,000 city residents, gathering their opinions on culture, nightlife, food, and quality of life.
They also rated their city based on these five statements: "My city makes me happy; I feel happier in my city than other places I've visited or lived; The people in my city seem happy; I find joy in the everyday experiences my city offers; The sense of happiness in my city has grown a lot recently."
88% of locals in Hanoi said that their city brings them joy.
India's Mumbai is voted the happiest city in Asia, followed by China's Beijing and Shanghai.
Indonesia's Jakarta ranked sixth while Hong Kong secured 7th spot, followed by Thailand's Bangkok at 8th, Singapore at 9th and Seoul at 10th.