Frequently Occurring First Names in the 2020 Census is the second U.S. Census Bureau data product listing the most common first names reported in the decennial census. The previous data release, after the 1990 Census, was based on results from the post-enumeration survey rather than the census itself (U.S. Census Bureau, 1995). This 2020 product is derived from the 2020 Census results, using methods developed for last name review since 2000. The 2000 methodology was revised for the 2010 last name product (Comenetz, 2016) and further revised for 2020. This document first summarizes the methodological changes between 2010 and 2020, then describes the 2020 results and compares them with data from previous decades.