I am 14 and I want to know at what age can you choose which parent you want to live with? I live in Australia?

You, the same as the parents are bound by the legal court order. You can not just decide different.

You can at 14, testify in court, as to what you prefer, but both parents are allowed to also show, why you should or should not be allowed to.

So, to change custody, the parent without custody will have to file in court for a change in custody, which normally also effects child support payments.

You can decide where you want to live when you are 18. Until then, the court will listen to you as to what your choice is, but they will still rule in favor as to what they feel is in your best interest.

The age of majority in Australia is 18. At that point you can decide where you want to live. Which parent or on your own. Until then, you are subject to the ruling of a court as to who has custody over you. At 14, a court is likely to listen to your preference and the reasons for it, but they will make the decision. If a change is wanted then the non-custodial parent has to go to court to request a change in custody. If the non-custodial parent doesn't do this, then nothing will change.