Sigma Sigma is the St. Louis Alumnae Chapter of Alpha Chi Omega and is the Alpha Chi "home" to over 100 women from all over the St. Louis Community. The alumnae chapter supports the four Missouri collegiate chapters (Alpha Nu, Delta Chi, Delta Epsilon and Zeta Sigma) through volunteering, care packages and donations. Sigma Sigma is very proud to support the women and children of domestic violence through contributions to Our Little Haven and Lydia's House.

As a values-based organization with an emphasis in Sisterhood, Networking and Philanthropy, Sigma Sigma Alumnae Chapter is committed to providing a fulfilling and rewarding experience to any and every Alpha Chi Omega, no matter her age or initiated chapter.