Rosati-Kain was started after the School Sisters of Notre Dame and the Sisters of St. Joseph of Carondelet seperatly opened the Rosati Center and the Kain School and the two eventually merging around 1911. The sisters funded the school through charged needlework and music lessions. The school moved locations many times over the years, starting on Grand and Lucas, then moving in 1919 to Lindell and Newstead. Thanks to the hard work of the alumni association, the all girl school has been able to complete major renovations of its building starting around 1935.

The school flourished in educating young women. By the mid-1940’s, over 1,000 students attended Rosati-Kain in two different shifts, one in the morning and one in the afternoon. In 1947, Rosati-Kain became the first high school in the St. Louis area to integrate, years before Brown v. Board of Education was the law of the land.

Over the years, the school has seen much growth within the Catholic Archdiocese, with many renovations, student growth, and a swelling of alumni. In September of 2022,the Archdiocese announced that they would close Rosati-Kain High School. Within days, over 500 people, including Alumnae, current and former parents, and students, met in the gym to rally behind keeping the school open. A Board was formed by Alumnae who fundraised, negotiated a lease with the Archdiocese, and secured sponsorship by St. Joseph Educational Ministries. On Christmas Day 2022, the St. Louis Post Dispatch’s headline read: “The miracle on Lindell.” Rosati-Kain was staying open.

On July 1, 2023, Rosati-Kain Academy transitioned from the Archdiocese as an independent school. RKA is the only independent all-girls school in the city limits of St. Louis.