As others have said, Australian regional variation is nowhere near as great as even the US, let alone Britain.
(You mean Canada has regional accents?)
The main variation in Australia historically has been class-based (Cultivated, General, Broad), with less well-studied variation between rural and urban, and with an interesting in-group variant among 2nd generation immigrants (Barbara Horvath had studied it in the 80s (Variation in Australian English), and a bunch of Greek-Australian comedians made a career of it in the 90s; impressionistically, it was more about centralisation of vowels than nasalisation.)
People keep saying there is a Queenslander accent (a drawl), but I don’t hang around enough Queenslanders to know if that is something different from the urban–rural split, ay.
(OK, that was a joke: the “ay” is a Queenslander thing, but it’s not an accent thing.)
There *is* a regional phonetic difference that has crept up in the past twenty years: Victoria has a celery–salary merger, although you’ll find no Victorian admitting that New Zealand had it first. So celery here is pronounced /sæləri/, and Melbourne is pronounced /mælbɪn/. Bizarrely when linguists noticed it, they called it Melbourne raising, even though it’s always sounded to me like the /ɛ/ lowering, not the /æ/ raising.