A jury deliberated for only two hours before reaching the verdict.
The Los Angeles County district attorney said Little murdered three women, Carol Alford, 41, found dead July 13, 1987; Audrey Nelson, 35, whose body was discovered Aug. 14, 1989; and Guadalupe Apodaca, 46, from Sept. 2, 1989.
Little was arrested in Kentucky in 2013.
Little, also known as Samuel McDowell, is also suspected of murder and attempted murder in Florida and Mississippi.
He is facing life in prison without parole and will return to court Sept. 25 to be sentenced.