Australia’s immigration laws offer visas to foreigners who are in relationships with Australians.
​However, the rules are very complex.

You must seek legal advice about your personal circumstances. Only an
experienced immigration lawyer or agent is qualified to give you the correct
advice about whether marriage will help your application or not.

​Australian residents can bring a partner to Australia on a Fiancé or
Prospective Spouse Visa. You are required to lodge a Notice of Intended
Marriage (NIM) with an Authorised Marriage Celebrant within the minimum
one month of your nominated date of marriage. The date nominated for 
your wedding can be changed if the visa is not granted in time – your NIM is
valid for 18 months. The Celebrant will issue you with a letter addressed to the
appropriate Australian Embassy handling the applicant’s case, confirming
that s/he has received that Notice, the date and location of the wedding and
that you have paid a non-refundable deposit. You or your partner lodges this letter
with their visa application at the embassy in the country from where they are
applying.