Brendan Reilly (born December 26, 1971[1][2][3]) is an American politician who has served as alderman of Chicago's 42nd ward since 2007, when he unseated septuagenarian incumbent Burton Natarus.

[2] In 2001, Reilly served as press director of Paul Vallas's campaign in the Democratic primary of the 2002 Illinois gubernatorial election.

[6] Reilly serves as a board member of the Energy Foundry, a non-profit venture capital fund dealing with green technology.

[10] In the 2020 Cook County State's Attorney election, Reilly endorsed Bill Conway in his primary challenge against Kim Foxx, the Democratic incumbent.

After Conway lost 50-31, Reilly endorsed Republican former Cook County Judge Pat O'Brien in the general election instead of backing Foxx.