James Thompson Maffett (February 2, 1837 – December 19, 1912) was a Republican member of the U.S. House of Representatives from Pennsylvania.

He attended the common schools, Rimersburg Academy, and Jefferson College in Canonsburg, Pennsylvania (now Washington & Jefferson College).

He taught school in Missouri for one year, and then, in 1859, moved to California, where he taught school in Amador County and began the study of law.

He was admitted to the bar in Brookville, Pennsylvania, in 1872 and commenced the practice of his profession in Clarion.

Maffett was elected as a Republican to the Fiftieth Congress.