Same-sex couples in Tasmania will be able to make their marriages official from 1 November, its government has announced.

While gay couples have been able to register their relationships formally since 2003, the new legislation will mean celebrants can perform the ceremony.

Tasmania's Gay and Lesbian Rights Group spokesman Rodney Croome tells ABC News that the move sets a national precedent.

Same sex couples will "be able to declare and affirm their relationship in front of a marriage celebrant and their family members and their friends, which is very important for some couples to be able to publicly make those vows and form now on that will be possible," he says.