Robert Shelden Brewer Jr. (born April 30, 1946) is an American attorney who served as the United States Attorney for the Southern District of California from 2019 to 2021.

Prior to law school, Brewer served in the United States Army as an Airborne Ranger and received the Silver Star and two Bronze Stars for his service in the Vietnam War.

Brewer previously served as a Deputy District Attorney in Los Angeles County from 1975 to 1977, and as an Assistant United States Attorney in the Central District of California from 1977 to 1982, where he successfully prosecuted a variety of cases including espionage, bank robbery, murder for hire, and aircraft hijacking.

He held various management positions, including Assistant Chief of the Criminal Division.

[4] On June 20, 2018, President Donald Trump nominated Brewer to become the next United States Attorney for the United States District Court for the Southern District of California.