The person recently traveled to Liberia and had been showing one symptom consistent with Ebola and other diseases, FOX 4 learned Friday afternoon.
Tarrant County officials wouldn't say where the person was being monitored.
The last known case of Ebola in Liberia was in late March, according to officials.
Thomas Eric Duncan died at Texas Health Presbyterian Hospital in Oct. 2014 after contracting Ebola and coming to the United States. Two of Duncan's nurses, Nina Pham and Amber Vinson, also came down with the disease but survived.