I have previously mentioned Wedderburn. Wedderburn airfield has a single runway, 17/35 measuring approximately 950 m (3,120 ft) long. There are some interesting historical pics in the Sport Aircraft Club's gallery from the Campbelltown City Council collection. It's a post-war private field that has grown somewhat since closure of Hoxton Park.
I should mention Wallacia. Wallacia airstrip was on Park Rd, Wallacia. It is no longer in use, indeed it's not really visible to me at all - not a trace! I also have found little historical information on ownership or use. I do know that it was adjacent to a Wildlife Park (Bullen's Animal World) and was used as carparking during a music festival in 1971.
Wikipedia says this about Bullen's Animal World:
Bullen's Animal World was a circus style theme park located at Wallacia on the outskirts of Sydney. Its address was 11 Park Road, Wallacia. It was opened in 1969 by Stafford Bullen, the son of circus founder Alfred Percival Bullen, and operated until 1985.
And there's Wilton, of course, an active former WWII "dispersal strip" with 3 crossing runways in a triangular arrangement. At least 2 runways are visibly operational. Wilton is a skydiving centre with some growth occuring since the closure of Hoxton Park airstrip. Wilton is located along the Hume Motorway, south-west of Sydney.
"2nd" major airport for Sydney but after much opposition and consternation plus decades of indecision Badgery's Creek is the current formally selected and 'semi-funded' site. We'll see what happens, I guess!
My list of Sydney's race tracks and circuits.or checkout my list of Sydney and surrounding airstrips and airports.