Elizabeth Choy-Yong Su-Moi OBE (Chinese: 蔡杨素梅; pinyin: Cài-Yáng SùMéi) was a Singaporean war heroine, educator and councillor. Along with her husband, Choy Khun Heng, she supplied medicine, money and messages to British civilians interned in Changi Prison during the Second World War.

Elizabeth Choy-Yong Su-Moi was born on 29 November 1910 to a Hakka family in Kudat, British North Borneo. Her great-grandparents first came to Kudat from Hong Kong to assist German missionaries in their work. The eldest of 11 children, Choy's father worked as a civil servant after completing his early education in China with some English education in North Borneo, where he married the daughter of a priest. He transferred to work in Jesselton and was later promoted to District Officer, moving to Kalimantan.

Choy was looked after by a Kadazan nanny and acquired Kadazan as her first language.She became an Anglican at St Monica's boarding school in Sandakan, where she took the name Elizabeth, and went on to complete her education at Raffles College in Singapore. As her family could not afford the fees, she started to teach, first at St Margaret’s School and then at St Andrew’s.