Ronald Adrian Nirenberg (born April 11, 1977) is an American politician and the former mayor of San Antonio, Texas. Prior to his election, Nirenberg served as a member of the San Antonio City Council for District 8 for two terms.

In 2013, Nirenberg was first elected in an upset victory to represent district 8 of the San Antonio City Council. Nirenberg was elected mayor in 2017, defeating incumbent Ivy Taylor, and was sworn in as the mayor of San Antonio on June 21, 2017. He was narrowly re-elected in 2019 facing Greg Brockhouse, a city councilman critical of his policies. In the 2021 mayoral election, again, against Brockhouse, Nirenberg won with 61.89% of the vote. In the 2023 mayoral election, Nirenberg won his fourth and final election as mayor, with unofficial results of over 61% of the vote.