James Davis Porter, Jr. (December 7, 1828–May 18, 1912) was governor of the U.S. state of Tennessee from 1875 to 1879.

A native of Paris, Tennessee, Porter graduated from the former University of Nashville at age 18. He was elected to the Tennessee General Assembly in 1859. When the American Civil War loomed, Porter sided with the Confederacy. He was involved in the organization of the Provisional Army of Tennessee. After his civil rights were restored he was elected a circuit judge, and served as such until his election as governor. His administration was greatly hampered by the high level of state debt relative to the size of the state's economy at the time, and the various approaches suggested for dealing with the state debt were the major issues during his administration.

Porter was a strong supporter of public education. While he was governor, the first medical school for emancipated blacks, Meharry Medical College, was founded in Nashville. During Porter's tenure as governor, the so-called "Four Mile Law " was adopted. An early, backdoor form of Prohibition, it forbade alcoholic beverages within four miles (6.4 km) of any school; given the small size of most of the schools of the era and their resultant presence in almost every community, even many of the smallest ones, this effectively outlawed alcohol in all but the least-populated areas of the state, which was exactly the intent of the measure's sponsors.

Porter was a Democrat and was later U.S. Minister to Chile.