The single-engine aircraft went down shortly after 10 a.m. at the Newhall Avenue exit in Newhall. Flames ignited after the plane struck a tree, according to a California Highway Patrol log.
Witnesses' video from the scene showed a large plume of black smoke rising above the mangled wreckage in a grassy area near the off-ramp.
The cause of the crash and the identity of the pilot, who was pronounced dead at the scene, were not immediately known.
The northbound 14 in Southern California was closed as a result of the incident.