Using data from 810 women entering the Department of Women’s Justice Services in the Cook County Jail (Chicago) from 2010 to 2013, this study examines patterns of trauma exposure and the relationship between trauma exposure and mental disorders. Female detainees averaged 6.1 (SD = 4.90) types of trauma in their lifetimes, with greater trauma exposure associated with earlier age of trauma onset, more recent trauma exposure, and higher rates of fear for life or injury. Higher rates of trauma exposure were also correlated with higher rates of past-year symptoms of posttraumatic stress disorder as well as other internalizing, externalizing, and substance use disorders. Behavioral health programming for female detainees in jail settings should include more trauma-sensitive mental health and substance use disorder treatments.