Yes, cousin marriage is legal in Australia, but subject to strict familial relationship prohibitions and state-based registration requirements.
Cousin marriage is permitted under federal law, provided the parties are not within prohibited degrees of consanguinity. The Marriage Act 1961 (Cth) and state-based Relationships Act frameworks (e.g., Relationships Act 2008 (Vic), Relationships Act 2011 (Qld)) enforce these restrictions. The Australian Bureau of Statistics (ABS) reports no criminalization of cousin unions, though compliance with registration obligations remains mandatory. Recent 2026 amendments to the Family Law Act 1975 (Cth) reinforce genetic counseling prerequisites for marriages involving first cousins, aligning with public health advisories from the Department of Health and Aged Care.
Key Regulations for Cousin Marriage in Australia
- Prohibited Degrees of Relationship: The Marriage Act 1961 (Cth) s 23B explicitly bars marriages between lineal ancestors/descendants (e.g., parent-child, grandparent-grandchild) and siblings, but permits first cousins unless state laws impose additional restrictions.
- State-Based Registration Mandates: Victoria’s Relationships Act 2008 and Queensland’s Relationships Act 2011 require formal registration of cousin unions for legal recognition, with penalties for non-compliance under the Births, Deaths and Marriages Registration Act 1996 (NSW).
- 2026 Genetic Counseling Requirement: From 1 July 2026, couples seeking cousin marriage must provide a genetic counseling certificate from an accredited provider, as mandated by the Family Law Amendment (Genetic Testing) Regulations 2025 (Cth), to mitigate hereditary risk disclosures.