James Christopher Dunn (September 11, 1866 – June 9, 1922), also known as "Sunny Jim" Dunn, was a businessman and baseball team owner of the Cleveland Indians from 1916 until his death in 1922, during which time the team won its first World Series in 1920.

[citation needed] Dunn was born in Marshalltown, Iowa and became wealthy through his partnership in a railroad construction firm.

In 1916 he was recruited by American League president Ban Johnson and his secretary, Bob McRoy, to head up a syndicate to buy the Cleveland Indians baseball team from Charles Somers for $500,000.

[1] During his tenure the team's ballpark League Park was renamed "Dunn Field" and in 1920 the Indians won their first World Series.

[3] In 1927 ownership of the Indians changed hands when Dunn's widow Edith, by then known as Mrs. George Pross, sold the franchise for $1 million to a group headed by Alva Bradley.