John Daniel Custance FCS FRAS was an agricultural scientist, founder of Roseworthy College, South Australia, but was sacked by a Minister with whom he had mutual antipathy.

Roseworthy Agricultural College was an agricultural college in Australia. It was 50 km (31 mi) north of Adelaide and 7 km (4.3 mi) west of Roseworthy town. It was the first agricultural college in Australia, established in 1883. It is now part of the University of Adelaide.