The age of consent for all sexual acts will be standardised to 16 years in Queensland.
The state's parliament has voted to lower the age for anal sex from 18 years, bringing it into line with the age of consent for other sexual acts.
The Criminal Code will also be amended to replace references to "sodomy" with "anal intercourse" after the Queensland AIDS Council said the former term had connotations of outdated laws and moral standards.
Queensland is the only state in Australia to have different legal ages of consent for anal and vaginal sex.
Health Minister Cameron Dick said the amendments were aimed at improving sexual health.
"Too often the conversation about the age of consent has focused on morality and, worse still, on criminality," he told parliament.
"(With these amendments) we remove a discriminatory provision from our statute books and support the sexual health and wellbeing of young Queenslanders."
The Liberal National Party did not oppose the changes but expressed concerns about how young people would be educated about them.
"We do need certainty and clarity from the government as to how it will educate the 16- to 17-year-old cohort around these changes," opposition health spokesman John-Paul Langbroek said.
Queensland AIDS Council executive director Michael Scott welcomed the reform, saying an unequal age of consent had been a barrier to equal access to healthcare.
"We are concerned that with the current inequality of age of consent, young people who are sexually active are reluctant to access sexual health services including HIV and other STI testing and preventative health education for fear of being prosecuted," he said.
The standardisation of age of consent for sexual acts will bring Queensland into line with other jurisdictions.
