Ngọ was born in Hanoi in 1931.[2] Her father, Trịnh Định Kính, was a successful businessman who owned the largest glass factory in French Indochina.[3] She later stated that she grew eager to learn English because of her desire to watch her favorite films such as Gone with the Wind without subtitles. Her family provided her with private lessons in English. In 1955, when she was 24 years old, she joined the Voice of Vietnam radio station and was chosen to read the English language newscast aimed at listeners in Asia's English-speaking countries.[3][4] One of her tutors and mentors at the station was Australian journalist Wilfred Burchett.[3] At this time, she adopted the alias Thu Hương, meaning "autumn fragrance", as it was easier and shorter for her non-Vietnamese listeners.[4]