The Alma Mater is "virtue, honor, and education."
The school was founded in 1851 by the Sisters of St. Francis and Mother Teresa Hackelmeier.
Oldenburg Academy received its commission as a high school in 1910.
Currently, the school is controlled by a board of trustees rather than the original owners, the Sisters of St. Francis.
In 2020, the academy constructed a new athletic facility named the Hillenbrand Family Feldhaus.