John Richard (Jack) Collins, (born 1 August 1932 in Melbourne, Victoria) was an Australian cricket Test match umpire.
He umpired five Test matches between 1972 and 1975. His first match was between Australia and Pakistan at Melbourne on 29 December 1972 to 3 January 1973, won by Australia by 92 runs with Ian Redpath, Greg Chappell, Paul Sheahan, and John Benaud all scoring centuries. Collins' partner in this match was Peter Enright, also standing in his first Test match.
In the preceding season, 1971/72, a scheduled tour of Australia by South Africa was cancelled following political and moral protests against the apartheid policies of the South African government. In its place a 'World Team' visited Australia and played a series of Test standard, although never officially recognised. Collins stood in one of these matches, and witnessed Garfield Sobers score 254, an innings he later regarded as the greatest he ever saw.
Collins' last Test match was between Australia and the West Indies at Melbourne on 26 December to 30 December 1975, won by Australia by 8 wickets with centuries to Ian Redpath and debutant Gary Cosier, with Dennis Lillee and Jeff Thomson taking 13 wickets between them. Collins' colleague was Robin Bailhache.
Collins also umpired one One Day International match in 1979.