Mountain Brook is a city in southeastern Jefferson County, Alabama, and a suburb of Birmingham. According to the 2010 census, the population of the city is 20,413. Mountain Brook is an affluent city within the Birmingham metropolitan area that is convenient to downtown Birmingham, Samford University, and the University of Alabama at Birmingham.

Mountain Brook was originally developed in 1929 by local developer Robert Jemison as an extensive residential subdivision, and was incorporated on May 24, 1942. The plans, by Boston-based landscape architect Warren H. Manning, called for estate-sized lots along winding scenic roads and denser commercial development centering on three "villages" known as English Village, Mountain Brook Village. and Crestline Village. Most of the development of Mountain Brook preserved the existing trees. Ninety-two percent of the city is under tree cover, one of the highest ratios in the nation.

Mountain Brook has a city council/mayor/city manager system of government. The city council consists of five members elected at large, and the council considers most issues and appoints the police chief, fire chief, and city manager (with the mayor). Stewart Welch is the current mayor, having taken office in 2016. Administrative business is handled by the city manager, a position held currently by Sam Gaston.