How Do I Get Married In Australia, And What The Legal Requirements Are?

You are strongly advised to contact the nearest Australian Embassy or consulate to confirm these details, as they may not be complete and are subject to change.

Minimum age=18, although sometimes courts may allow younger in exceptional circumstances.

Minimum one day's residence in Australia prior to the ceremony.

A Notice Of Intention To Marry must be filed at least one month plus one working day (but less than 6 months) before the intended wedding date.  

Each person getting married also needs

A Birth Certificate
A valid passport if not an Australian citizen
The original copy of the Notice Of Intention To Marry
If divorced, proof that the previous marriage is annulled.
If widowed, death certificate for previous spouse, and previous marriage certificate.
Legal proof of any name changes

The marriage ceremony must be conducted by someone who is a registered marriage celebrant.  This could be a religious minister, a State Registrar, or another authorised person.

In order for the marriage to be valid, within 14 days of the ceremony an official certificate of the marriage must be sent to the district registrar in the State in which the marriage took place.