Gender recognition is a crucial achievement for non-binary people. To better understand this right, this article combines comparative law with theoretical insights from anthropology to offer a discussion of non-binary recognition in European fundamental rights law. It identifies three approaches to such a right and critically assesses each of them. The first approach is denial, with the non-binary option being explicitly or implicitly rejected, as has occurred in French and Italian courts. The next approach is limited recognition, whereby a non-binary option is granted under specific limitations, such as when certain physical characteristics are present or when a claimant permanently identifies with the non-binary gender. This is the course of action that has been taken in German law. The third approach is gender self-determination, whereby individuals can obtain recognition on the basis of their declaration alone. This solution has been offered by the Belgian Constitutional Court. On the strength of findings from anthropology, the article argues that the first two models are incapable of genuinely engaging with gender diversity, while the third one offers more robust legal protection. The analysis presented here serves as an example of how anthropological insights can be effectively used to advance comparative law research.