Newellton is a town in northern Tensas Parish in the northeastern part of the U.S. state of Louisiana. The population is 1,227 in the 2010 census, a decline of 255 from 2000. Newellton is some 65 percent African American. It is just west of the Mississippi River on Lake St. Joseph, an ox-bow lake. Further south toward St. Joseph is Lake Bruin, another ox-bow lake, a part of which is the popular Lake Bruin State Park.
The French explorer La Salle passed through the Newellton area in 1682 as he followed the Mississippi River to its mouth near the future New Orleans.
Newellton itself was founded in the early 19th century by the Routh family, for whom the defunct Routhwood Elementary School was named. John David Stokes Newell, Sr. (1837–1899), a planter and lawyer in St. Joseph, the seat of Tensas Parish, named the settlement for his father, Edward D. Newell (1810–1888), a native of North Carolina who relocated to Tensas Parish in 1834.