The U.S. Census Bureau has never surveyed individuals regarding their sexual orientation. For the first time, however, in the 2020 census, the agency has given individuals the opportunity to identify their relationship as same-sex. This only allows us to number those in household relationships.
The most informative survey offering any view of Los Angeles County’s LGBTQ population was a Gallup survey of more than 374,000 people, conducted from June 2012 through December 2012, that asked the question, "Do you, personally, identify as lesbian, gay, bisexual or transgender?" The survey focused on the 50 largest metropolitan areas in the United States, including the Los Angeles area. The Gallup survey found that the Los Angeles-Long Beach-Anaheim metropolitan area (Los Angeles and Orange Counties) ranked eighth among America’s 50 largest metro areas, with 4.6 percent of its population identifying as LGBTQ. At the time, Gallup put the national average at 3.6 percent, although, its 2020 survey updated that to 5.6 percent (likely also increasing the L.A. metro area percentage).
If we were to apply the 4.6 percent survey finding against the most recent U.S. Census estimate (2019) for Los Angeles County’s adult population, we would identify approximately 361,873 adult residents of the county as LGBTQ. About the same time, a 2012 report by the Los Angeles County Department of Public Health estimated that approximately 14,428 county residents are transgender.
The U.S. Census has, until 2019, provided estimates for number of households in which unmarried partners are same-sex. In 2019, that estimate came to 15,606. This number, however, came in at about half the census count of same-sex partner households in the 2010 Census (32,704). Of those 32,704 same-sex households in 2010, 25 percent had related children under the age of 18.