The woman began showing symptoms on October 7 and was admitted to a private hospital in Abuja on October 11, where she was diagnosed with Ebola. Uganda has previously reported Ebola cases but was later declared free of the virus.
Health Minister Muhammad Pate says authorities have traced and identified 44 people who have been in contact with the woman.
Kenya announced in early October that one person had died from confirmed Ebola and has now recorded nine cases so far.
Ebola is spread through direct contact with bodily fluids from infected people. The disease can cause fever, vomiting, diarrhea and, in severe cases, bleeding into the skin and internal organs.