What is a marriage celebrant?

In basic terms, a marriage celebrant (in Australia at least) is a person who is authorised to perform marriages. We are registered by the government to perform the requirements under the Marriage Act 1961 that create a legal marriage.
Types of marriage celebrants
There are four kinds of celebrants under the Marriage Act.
Ministers of religion of recognised denominations
Think Catholic priests and Muslim imams. These celebrants are registered by the State and Territory Governments on a geographical basis. The way I understand it is the religious organisation basically says to the relevant government we have this many parishioners in this area, therefore we need this many authorised marriage celebrants to manage the workload, and we nominate these ministers to fulfil those roles. Most ministers of religion will only perform marriages in their religious building. Their ceremonies must adhere to their religious organisations requirements and cannot stray outside those.
State and Territory Officers
These are the people who work in the State/Territory Marriage Registries and the Registrars at some regional courts. They’re only allowed to perform marriages on behalf of their employer (the relevant State/Territory Government) at the places provided for in their letter of registration.
Commonwealth Registered Marriage Celebrants
That’s me, and other civil celebrants like me. We’re registered by the Commonwealth Attorney-General’s Department after completing a Certificate IV in Celebrancy and applying for registration. We can perform weddings wherever and whenever you want us to. As long as our ceremonies contain the legal requirements, pretty much anything else goes.
Commonwealth Registered Religious Marriage Celebrants
These are ministers of religion of non-recognised denominations AND former civil celebrants whose religious beliefs did not allow them to perform marriage equality weddings. The latter category was only open to existing celebrants when marriage equality was legislated on 9 December 2017. They had three months to say their religious beliefs would not allow them to perform such marriages. They are now allowed to say no to such couples without being sued for discrimination. Ministers of religion of non-recognised denominations can still apply for registration under this category after completing the Certificate IV in Celebrancy.
Other types of celebrants
There are other kinds of celebrants too, including funeral celebrants and life celebrants. However none of them have to be registered by any government to undertake their roles.
What else does a celebrant do?
So that’s the boring legal stuff about marriage celebrants, but our role is much more than that. Check out this little video I made for my Certificate IV in Celebrancy students. Enjoy!