Archibald Millar Robertson Sim (born 8 January 1942) is a former South African cricketer.
Sim was a right-handed batsman who bowled right-arm medium pace.
He was born at Johannesburg, Transvaal Province.
Sim made his first-class debut for North Eastern Transvaal against Rhodesia in the 1962/63 Currie Cup.
He made two further appearances in that season's competition, against Border and Rhodesia.
In his three appearances, he scored 45 runs at an average of 9.00, with a high score of 17.
He played county cricket for Northamptonshire in 1964, making his first-class debut for the county against Cambridge University.
He made a further appearance in 1965 against Oxford University, before making two further appearances in 1966 against Oxford University and Nottinghamshire.
In his four first-class appearances for Northamptonshire, he scored 151 runs at an average of 25.16, with a high score of 66 not out, which came against Oxford University in 1965.