Ian Robert Cathie (born 24 October 1932) is a former Australian politician.
Born in Melbourne to printer George Mitchell Cathie and Sybil Balding, he attended state schools and then the University of Melbourne, where he studied teaching. On 5 January 1957 he married Christine Watson, with whom he had four children; he married again on 3 July 1976 Jean Germain, an industrial nurse. He was president of the Peninsula Victorian Teachers Union in 1959 and taught at Frankston and Mordialloc High Schools, as well as serving on the council of Monash University from 1977 to 1982. In 1964 he was elected to the Victorian Legislative Council as a Labor member for South Eastern Province; he was defeated in 1970, but in 1976 was elected to the Legislative Assembly seat of Carrum, which he held until 1988.[1]