Transgender and gender diverse Tasmanians can now change the gender on their birth certificate without needing surgery, or remove it completely.
Tasmanians can now choose whether their gender is included on their birth certificate.
The change kicks in on Thursday after state parliament passed laws in April making Tasmania the nation's first jurisdiction in which gender on a birth certificate is optional.
The laws also removed the requirement for transgender people to have sexual reassignment surgery in order to have a new gender recognised.
That brought Tasmania into line with the Australian Capital Territory, Northern Territory, South Australia and Western Australia.
The Victorian parliament also voted in favour of such a change in June.
Tasmanian's aged 16 years or older can apply to change their registered gender without parental approval.
The Liberal state government had opposed the changes, but the legislation passed the lower house on the casting vote of Liberal Speaker Sue Hickey, who crossed the floor.
Transgender and gender diverse advocates plan to mark the laws coming into effect with cupcakes and champagne at the Registry of Births, Deaths and Marriages in Hobart.