Ong Eng Guan (Chinese: 王永元; pinyin: Wáng Yǒngyuán; 1925–2008) was a Singaporean politician who served as Minister for National Development between 1959 and 1960. An anti-communist, Ong was a Chinese-educated orator who became popular among the Chinese community in Singapore. He was also one of the pioneering members of the governing People's Action Party (PAP). He was elected into the City Council of Singapore and became the first and only elected mayor in Singapore's history after the 1957 City Council election.