The basic user profile for members in the United States now includes a customizable category among the gender types that users must select, the world's No.1 Internet social network announced on Thursday, the day the feature became available for U.S. members using the site's English-language version.
Those who select that option can select up to 10 gender identifications, including "transgender," "intersex" and "fluid."
The company said it worked with a leading group of gay and transgender advocacy organizations to come up with the selection of identity options.
Until now, Facebook's 1.23 billion members could only select male or female for their genders, which Facebook requires users to state in their profiles. Users of rival Google Inc's Google+ social network already had an "other" option for gender.
Facebook said users also can control the audience who can view a custom choice, noting the challenges that some people may face in publicly sharing their gender identity.
Users can also choose the personal pronoun to which they are referred publicly. A message on Facebook might now invite a user's friend to write a birthday message on "their" wall, instead of "his" or "her" wall.
"We want you to feel comfortable being your true, authentic self," Facebook said.