The 1991 Australian Under-21 Individual Speedway Championship was the 5th running of the Australian Under-21 Individual Speedway Championship organised by Motorcycling Australia.
The final took place on 6 January 1991 at the Olympic Park Speedway in Mildura, Victoria.
Shane Parker from Adelaide was second with another Mildura rider Jason Lyons in third place.
Parker defeated Lyons in a run-off for the minor placings after both finished the meeting on 13 points.
Former South Australian champion Scott Norman defeated Dave Hamnett from New South Wales in a run-off for fourth place after both finished the meeting on 11 points.