It's a work in progress, but here goes....
Crit circuits and velodromes in the Hurstville area:
Olds Park, Penshurst (cycling circuit around circumference of park). Raced at least once, possibly during a Commonwealth Bank Cycling Classic in the late '80s?)
Kempt Field, another Commonwealth Bank Cycling classic stage venue. Narrow track in parts with some twists, sandy edges and a steep-ish climb every lap.
And - reportedly - there was a small, steep indoor velodrome at Railway Parade, Carlton. The building appears to have gone/been remodeled but I did check it out on the early 1980s when it was an art warehouse. It was certainly old, full of iron spars and posts but there was hardly enough space between the ironwork to race track bikes... surely? More investigation needed.
Crit circuits in the Sutherland area:
Waratah Park - Sutherland Club - several useful criterium loops including the main, long circuit that drops way, way down (ie potentially very fast) and turns hard left before climbing back up to the main straight.
Crit circuits and velodromes in the Eastern Suburbs:
Riley Street (old, long-lost, steep timber velodrome, later moved to Canterbury)
Heffron Park, home of Randwick-Botany and Eastern Suburbs clubs, a 2.2km circuit with plenty of twists, a hill and a long, long finishing straight.
Coogee - a street circuit used in the Commonwealth Bank Cycling Classic
Bondi Beach - the promenade, used by the Randwick Club before traffic got the better of it all
Bunnerong Road - a road course used after Bondi beach was no longer available but before Heffron came about
Centennial Park - a regular venue for road championship cycling.
Western and Inner Western Sydney crit circuits and velodromes:
Merrylands Oval (saucer velodrome)
Canterbury (old Riley Street timber velodrome, moved)
Tempe (or Canterbury velodrome, a concrete twin of Chandler in Brisbane)
Wiley Park (banked outdoor velodrome lost to road widening)
Bass Hill (crit track and indoor timber velodrome)
Camperdown (now closed, a concrete velodrome that replaced the Empire Games track at Henson Park)
Blacktown criterium track
Lidcombe Oval (outdoor velodrome)
Lansdowne Park, a twisty criterium course with a decent hill
Henson Park (the 1938 Empire Games velodrome)
As always, more soon...
My list of Sydney's race tracks and circuits.or checkout my list of Sydney and surrounding airstrips and airports.