James Philemon Holcombe was an American law professor, legal author and Confederate politician and diplomat.

James Phinney Baxter was an American politician, businessperson, historian, civic leader, and benefactor of Portland, Maine. He was elected as mayor of Portland for six single-year terms between 1893 and 1905.

James Phinney Munroe was an American author, businessman, professor and genealogist of the Clan Munro. He attended the Massachusetts Institute of Technology and graduated in 1882, although remained active in the affairs of the school. He published a number of mostly scholarly works. He was the father-in-law of Frederic Lansing Day who married his daughter Katharine. Munroe, who lived in Lexington, Massachusetts, was a president of the Lexington Historical Society and Treasurer and President of the Munroe Felt and Paper Company. He edited the second edition of Charles Hudson's History of Lexington.

James Robinson Planché was a British dramatist, antiquary and officer of arms. Over a period of approximately 60 years he wrote, adapted, or collaborated on 176 plays in a wide range of genres including extravaganza, farce, comedy, burletta, melodrama and opera. Planché was responsible for introducing historically accurate costume into nineteenth century British theatre, and subsequently became an acknowledged expert on historical costume, publishing a number of works on the topic.

James D. Ployhar was an American composer, music educator, and film producer. He was responsible for many pieces of music well known to American band students, including "Cool Blues for Trumpets", "March of the Irish Guard", "Crazy Clock", and "Korean Folk Song Medley".

James Plunkett Kelly, or James Plunkett, was an Irish writer. He was educated at Synge Street CBS.

James Pounder Whitney was a British ecclesiastical historian.

James Preller is an American writer of children's books including Bystander, Six Innings, and the Jigsaw Jones Mysteries.

James Otis Purdy was an American novelist, short-story writer, poet, and playwright who, from his debut in 1956, published over a dozen novels, and many collections of poetry, short stories, and plays. His work has been translated into more than 30 languages and in 2013 his short stories were collected in The Complete Short Stories of James Purdy.

James Quinn Wilson was an American political scientist and an authority on public administration. Most of his career was spent as a professor at UCLA and Harvard University. He was the chairman of the Council of Academic Advisors of the American Enterprise Institute, member of the President's Foreign Intelligence Advisory Board (1985–1990), and the President's Council on Bioethics. He was Director of Joint Center for Urban Studies at Harvard-MIT.