The jet-cooled o-chlorobenzyl radical has been generated for the first time from o-chlorotoluene seeded in a large amount of inert carrier gas He and vibronically excited using a pinhole-type glass nozzle in a corona excited supersonic expansion. The vibronic emission spectrum of the o-chlorobenzyl radical in the D-1 --> D-0 transition has been recorded with a long path monochromator in the visible region. The spectrum has been analyzed to determine accurate electronic transition and vibrational mode frequencies in the ground electronic state by comparison with those from an A initio calculation as well as those of o-chlorotoluene.