Leslie Michael O'Connor (August 31, 1889 – January 20, 1966)[1] was an American lawyer and professional baseball executive.

[3] Born in Chicago, Illinois, O'Connor was admitted to the bar and served in World War I as a member of the Judge Advocate General's Corps.

[5] He then was named general manager of the White Sox by team owner Grace Comiskey and held that post for three losing campaigns.

After the White Sox lost 101 games and finished last in the eight-team American League in 1948, O'Connor stepped down and was succeeded by Frank Lane.

[3] During O'Connor's four-year term, the league replaced four teams located in the metro areas of those cities with clubs in Vancouver (Oakland Oaks), Salt Lake City (Hollywood Stars), Phoenix (San Francisco Seals) and Spokane (Los Angeles Angels).