Ernest Steven Monteiro CBE FRS BBM PJG FRFPS (21 December 1904 – 2 March 1989) was a Singaporean physician, specialised in preventive medicine.

[2] Monteiro was educated in St Anthony's School, Raffles Institution and King Edward VII College of Medicine.

[5] After completing his post-graduate studies on a Queen's Scholarship in 1949, he was elected head of Faculty of Medicine of the then University of Malaya, Singapore in 1956–1960.

[3][4] He divorced Una Marie Lewis, his first wife, in April 1971,[7] and secretly married Ling Mie Hean in August 1971 in Washington.

[9] The Republic of Singapore awarded him Bintang Bakti Masyarakat (BBM) in 1963 and the Pingat Jasa Gemilang PJG in 1968.