Bradford High School was named after Mary D. Bradford, Superintendent of Schools for the Kenosha school system starting 1910. Mrs. Bradford became the first woman in Wisconsin to serve as Superintendent of a major city school system. She served as Superintendent of Schools of Kenosha from 1878 to 1894, and again from 1910 to 1921. Mrs. Bradford, the former Mary Davison, was born in Kenosha County in 1856 and graduated from Oshkosh Normal School in 1876. She taught at Kenosha High School from 1876 to 1878. She became a member of the Board of Visitors of the Milwaukee Normal School in 1892, joined the new faculty of Stevens Point Normal in 1894, and joined the Faculty of Stout Institute in 1906. She then joined the faculty of Whitewater State Normal in 1909 where she served one year before returning to Kenosha. She retired in 1921 after 45 years in education. Mrs. Bradford died in Kenosha in 1943 at the age of 87.
The original Kenosha High School, later named Mary D. Bradford High School, was built in 1924 and is located at Sheridan Road and 57th Street. The building took three years to complete and opened in 1927. Mary D. Bradford High School occupied the site of the original Kenosha High School, later called the Mary D. Bradford High School Annex. The Annex was razed in 1980.
In 1975, the Kenosha Unified School Board purchased the former UW Extension Center located at 39th Avenue and Washington Road. This UW Extension Center was built in 1961 with an addition built in 1965. After its purchase by Kenosha Unified, a major addition was placed on the building in 1979 to include all of the components of a contemporary high school. After the 1979-80 school year, the Bradford building located on Sheridan Road was vacated and the building on 39th Avenue and Washington Road became the new Mary D. Bradford High School. Since that time, various maintenance projects have been undertaken along with the addition of two soccer fields north of the school, a softball stadium to the east and the new Mary D. Bradford Stadium, which opened in 2016.