Thought I'd leave a reply, as no one else has. I've never worked/lived in Canada, so don't know any specifics. That said, as an Australian who has worked in the UK, I can perhaps share my thoughts (not formal advice of course!)
I would guess the following two considerations would apply:
1. Tax residency in Australia
2. Tax treaties / Double tax agreement
Once you have Australian residency, have moved to Australia, have your home, work, family, etc. in Australia, then you would be considered an Australian tax resident for Australian tax purposes. Presumably on the Canadian side you would also be considered an Australian tax resident for Canadian tax purposes. (But you might want to check the specifics with a Canadian tax accountant.)
Assuming that's the case, then you will need to pay tax in Australia to the ATO on all foreign earnings including your foreign investment distributions and any Australian investments. However you can claim a
Foreign income tax offset on any foreign income which has already been taxed at the source. So if the Canadian Revenue Agency has already taken taxes out of your Canadian pension account, then you can claim that as an offset in your ATO tax return. You will still be taxed by Australian tax rules, but only after subtracting the offset amount, to compensate for the Canadian tax you already paid. This is thanks to the
income tax treaty which Australia has with a number of countries, including (I believe) Canada.
Regarding your Canadian pension funds -
My understanding is that in Australia, after retirement ("preservation age"), you don't normally have to pay capital gains tax on superannuation (which is the Australian equivalent of a government pension/retirement fund). To avoid paying CGT on your Canadian pension withdrawals you might need to move them to an Australian super fund.
It seems like it should be possible to transfer all of your foreign pension funds to an Australian Self Managed Super Fund (SMSF) in one lump sum, and from there, have it treated/taxed the same as regular super. (
Tax treatment of transfers from foreign super funds). I'm not sure if it's supported for Canadian funds. I guess you'd need to ask an Australian tax accountant about that.
If you prefer to keep your pensions in Canada and withdraw from them from Australia, I'm not sure whether you would be taxed on capital gains at that time, or whether it would be considered as super and you would not be charged capital gains tax. Also a question to ask an Australian tax accountant.
Hope it helps a bit!
