Thomas Hunter Campbell McDonell (born May 2, 1986) is an American actor, musician, artist and model. He co-starred with Eliza Taylor as Finn Collins, and Clarke Griffin, respectively, in "The 100", The Forbidden Kingdom alongside Jackie Chan and Jet Li, and in Twelve, starring Chace Crawford. McDonell played the main role in 2011 teenage film Prom as Jesse Richter, alongside Aimee Teegarden. He has guest-starred in Suburgatory as Scott Strauss, Tessa's boyfriend. He is the lead singer and guitarist for the band Moon. As a visual artist, McDonell has exhibited his own work internationally and has curated several exhibitions including a tunnel exhibit at the historic Southwest Museum site in Los Angeles and a video art show at a Best Buy in New York.

McDonell was born and raised in Manhattan, New York, and attended boarding school in Andover, Massachusetts. He graduated from New York University. His mother, Joanie, is a writer, and his father, Terry McDonell, is editor of Sports Illustrated. His brother is writer Nick McDonell.

McDonell starred as Finn Collins on the CW post-apocalyptic series The 100.