The sessions, from 9 to 11 a.m., and again at 6 to 8 p.m., introduce prospective parents and students to the school's programs and opportunities, said Jo Ann Cook, the president of the Alumni Association.
The open houses coincide with Catholic Schools Week, which starts Sunday.
It's also a historic time for the school, which celebrates its centennial anniversary in 2013. Its host church, Church of the Most Holy Trinity, marked its bicentennial this winter.
Enrollment at the school has grown since moving to a new location off Telfair Street.
"Currently, our enrollment stands at 105 students. Our goal was to pass the 100 mark and we made it," Cook said.
For 96 years, Immaculate Conception met off Laney-Walker Boulevard. The school dates to 1902, when Franciscan sisters opened an orphanage at 12th Street and Laney-Walker. In 1913, the African Mission Fathers built Immaculate Conception Church a block away and invited the sisters to bring the boarding school.
The school was moved again in the fall of 2009. It's now in the former Baird Building, where the Church of the Most Holy Trinity has its offices.
The move made room for a new computer lab and more bathrooms and classrooms, which will be available to tour Tuesday, Cook said.