If you are married to, the fiancée of, or in a committed relationship with (including same-sex partnerships) an Australian citizen or permanent resident or eligible New Zealand citizen, you may be able to obtain an Australian Partner Visa. You must have an Australian sponsor (usually your spouse or fiancée or partner) in order to apply, and they will pledge to support you financially and provide accommodation for your first 2 years in Australia on that visa.
If you are the fiancée of an eligible partner, you may apply for a Prospective Marriage Visa (subclass 300), which is a temporary visa valid for only 9 months, during which time you must marry your sponsor.
If you are in a committed relationship (de facto partnership), you must be able to prove that you have been in a de facto relationship and that you live together (or not apart on a permanent basis) for 12 months immediately prior to lodging your Partner Visa application.
You will be required to prove your relationship (nature of commitment, social aspects and financial commitment) and also pass the relevant health and character assessments. It is a two-stage process; you must simultaneously apply for both a temporary and permanent visa in the one application.
If you lodge your application outside Australia, you must be outside Australia when the temporary visa (subclass 309) is granted. Conversely, if you lodge your application in Australia, you must be in Australia when the temporary visa (subclass 820) is granted (should your previous visa have expired, you will be able to continue being resident on a bridging visa and may be entitled to multiple entry and exit as long as you inform the Department of Immigration).
If you are successful in your application for an Australian Partner Visa, you will be granted a two year temporary visa, which entitles you to work and live in Australia. Thereafter, if the relationship is still genuine and continuing, you may be eligible for permanent residence (subclass 100 if you applied outside of Australia, and subclass 801 if you applied from within). This two year requirement may be waived if you can prove that you have been in the relationship with your partner for 5 years or more, or if you have children and have been in the relationship for a minimum of 2 years.
Other Australian visa types:
Australian Skilled Migration Visas
Australian Business Visas
Australian Employer-sponsored Visas
Australian Investor Retirement Visa
Australian Student Visas
Australian Family and Spouse Visa
Australian Resident Return Visa
Australian Working Holiday Visa
Australian Travel Visa