Addison Foster Brennan (July 18, 1887 – January 7, 1962) was a pitcher in Major League Baseball. Brennan began his professional career in 1908 with the Springfield Midgets. He played in 1909 with the Wichita Jobbers, and had a win–loss record of 18–16 with them that season. After the season, the Cincinnati Reds purchased his contract without having seen him pitch. The Philadelphia Phillies traded for him in January 1910 due to finding this out, acquiring Brennan and Bob Ewing for Harry Coveleski and Frank Corridon.