Charles William "Jack" Harper (April 2, 1878 – September 30, 1950) was an American pitcher in Major League Baseball.

After a short stint with the Cleveland Spiders, he had a good season with the Fort Wayne Indians of the Interstate League in 1900 (going 20-15).

[2][3][4] By 1906, Chance had become the manager of the Cubs, and Harper was struggling on the mound.

Chance traded for Harper, cut his salary by two-thirds, and sat him on the bench for the entire season.

[5][6] At that time, organized baseball had the reserve clause; Harper had to pitch for the Cubs or no team at all.