Oscar Augustus Mitscher (June 7, 1861 – July 24, 1926) was a participant in the Oklahoma Land Run of 1889.

Oscar Augustus Mitscher was born on June 7, 1861, in Hillsboro, Wisconsin.

Very little about his early life has been published, other than that his parents were immigrants to Wisconsin from Germany, named Andreas Mischer and Constantina Mohn.

Their son, Marc Mitscher, became an admiral in the United States Navy.

The Shear family also lived in Hillsboro, Wisconsin, and made the Land Run of 1889.