James Madison Porter, American lawyer and politician, 18th United States Secretary of War (d. 1862)
James Madison Porter (January 6, 1793 – November 11, 1862) served as the 18th United States Secretary of War and was a founder of Lafayette College.

Porter began his career studying law in 1809 and later became a clerk in the prothonotary's office in an effort to manage a volunteer militia company at Fort Mifflin. Porter was admitted to the bar in 1813 and later appointed to attorney general for Northampton County, Pennsylvania. Throughout his life, Porter filled many roles. He was a professor of jurisprudence and political economy at Lafayette College (1837-1852), a judge of the twelfth judicial district (1839), ad interim Secretary of War under President John Tyler (1843), and was elected as a member of the Pennsylvania House of Representatives in 1849.