Do Australian academic jobs have similar tenure track policies as USA?
I don't want to contradict Samuel too much, but his account of what can happen has definitely happened to some people. But it is extremely rare and I would argue a little over-simplified.

For starters, my paycheck from a major Australian university has the word "tenured" on it. So my first point is, yes, continuing positions are "tenured" - but lets not get bogged down in semantics because tenure def means something different in Australia. Indeed I believe the union considers this to be a f(ph)urfy so let's say there is some subjectivity there.

Having tenure does not guarantee that you cannot be fired though. You can be. But as one manager said to me once, it is more expensive to fire an under performing academic than to simply retain them as long as they keep doing their teaching etc. I work with lots of unproductive academics and many have been asked to leave. They simply said no thanks and stayed. The only time I have seen academics forced out, they left with large redundancies and, simply put, wanted to leave. When you read about retrenchments at Australian unis in the newspaper, often more want to leave than are given packages.

Gross incompetence or dangerous behaviour? Yes you can be sacked. But as far as I have seen you cannot be fired on a "whim" as someone suggested. A business case would be made (declining enrolments, lack of research activity, lack of administrative roles)

And yes, as Samuel said, management teams will go after departments at times. But redundancy packages are often generous and often people from an eliminated department will be shifted to another department (good academics stay, crap ones move to a lower ranked uni).

I also don't want to make this a peeing contest, but I have worked in the US system too and the Australian system is more protectionist of staff than the US system. But indeed tenure is probably harder to lose than in Australia.

I am tenured at a Australian uni. I say this to people regularly and no one corrects me. But yes, I know union types that tell me my tenure is not tenure. I heard this a lot 5 years ago, but not recently

In short, to answer the initial question, the Australian system, broadly speaking, is the British system. Tenure with probation (3 years, recently raised to 5 I think)