The body of six-year-old Lazarus Alley was found by rescuers Thursday around noon, said Jeff Bishop of the Tennessee Wildlife Agency.
Lazarus, along with his seven-year-old sister Helana Alley and their father, Nick Alley, 36, had been missing since a boating accident in Polk County on Jan. 16.
The search continues for Helana and Mr. Alley.
Three other family members in the boat were able to swim to shore on the swollen Conasauga River a short distance from where it meets the Hiwassee River.
The Mennonite family is from Delano in Polk County.