Born in Chicago, Illinois, Crispin Freeman is the oldest of three children. He attended the Latin School of Chicago, where he graduated in 1990. He earned his Bachelor of Arts degree from Williams College, majoring in Theater and minoring in Computer Science. Afterward, he earned his Master of Fine Arts degree from Columbia University in Acting, and performed on Broadway (New York City), at the American Repertory Theater in (Cambridge), at the Mark Taper Forum in (Los Angeles), at Cincinnati's Playhouse in the Park, and at the Williamstown Theater Festival. As a child, Freeman was greatly influenced by anime shows such as Speed Racer and Battle of the Planets. Casey Kasem voiced the role of his favorite character, Mark of Battle of the Planets (he actually wanted to change his name to Mark at one point). Later, he discovered Voltron, Star Blazers, and Robotech, being quoted in the January 1999 issue of America Interview saying, "That show really blew me away." Freeman has also stated that the reason he got into the industry was because of the anime television show The Vision of Escaflowne. Freeman initially got involved in the anime voice-over industry when a friend of his landed a role in Peacock King.

Knowing Freeman was a big anime fan, a friend suggested he call up Central Park Media (CPM) and apply for a job doing English dubs. When originally approached about dubbing, he initially declined. It was not until he remembered all of the anime shows he watched as a child that he realized that many people are introduced to anime through the English dubbed versions. In 1997, Freeman landed the role of Zelgadis Graywords in Slayers along with Lisa Ortiz, Eric Stuart and Veronica Taylor. He was the second and final voice actor to get the job, after Zelgadis' original voice actor, Daniel Cronin, lost contact with CPM after a year-long halt in the dubbing. Years later he turned to the American animation voice acting grounds. He been best known for his work in Marvel Comics based productions such as The Spectacular Spider-Man, Wolverine and the X-Men and The Avengers: Earth's Mightiest Heroes. He then starred as several versions of Roy Harper in Young Justice for DC Comics and Warner Bros. Since then, Freeman has had various roles throughout his career. He has appeared in many video game titles as memorable characters, such as Albedo from Namco's Xenosaga series, the god of the sun Helios in God of War III, Haji, Joel the 6th and Van Argeno in Blood+, the main protagonist Baldur in Silicon Knights's Too Human, Breakdown in Transformers: War for Cybertron, the Winter Soldier in Marvel: Ultimate Alliance, and Iron Man in Marvel: Ultimate Alliance 2.