There is a person who was legally recognized as genderless.

Norrie May-Welby was officially recognized as sexless by the New South Wales registrar of Births, Deaths and Marriages. The 48-year-old was born a male but had a sex-change operation in 1990. Norrie currently identifies as neither male nor female and had Australian officials alter Norrie's birth certificate to reflect that. May-Welby admitted to being "grateful that at least the state of New South Wales is able to deal with me on such an adult basis". However, after receiving media attention for this historic first, the NSW reversed its decision and has deemed the altered birth certificate invalid.

(Sources: 1, 2, 3)