Ari Marmell is an American novelist and freelance role-playing game writer. He is known for his work in the genres of novels, short stories, role-playing games, and video games, with notable publishers such as Del Rey, Titan Books, Pyr Books, Wizards of the Coast, and more recently Omnium Gatherum. Ari's notable series include the Mick Oberon gangland/urban fantasy series and the Widdershins YA fantasy series.

In his personal life, Ari resides in Austin, Texas, in a home shared with his wife George and their cats. He is a graduate of the University of Houston. Born in New York, he opted for creative writing pursuits over schoolwork, which has shaped his successful career as an author.