Actor. Born in Clydebank, the son of actor Jimmy Copeland, Cosmo trained at the Royal Scottish Academy of Music and Drama and the Bristol Old Vic Drama School. He is noted for his red hair and bushy moustache.
Cosmo appeared in television classics such as Dr. Finlay's Casebook (1965) and Softly, Softly (1969), making his film debut in The Battle of Britain (1969) and The Virgin Soldiers the same year. He has had numerous other film roles, the most prominent being Highlander (1986), Braveheart (1995), Trainspotting (1996), Ivanhoe (1997), Troy (2004) and Greyfriars Bobby (2005).