The grandson and son of comedians George Stephenson 'Broncho' Wallace and George Stephenson Wallace (aka "Oncus"), George Leonard Wallace appeared on Harry Clay's Sydney circuit with his parents as a small child. After his mother left the act George Jnr continued to make guest appearances with his father up until 1924. After finishing school he initially pursued a career as a commercial artist, having studied at Sydney Technical College. This career was curtailed (and eventually abandoned when he began full-time service in the Australian Imperial Forces in 1941. After serving with the 1st Survey Regiment Wallace was transferred the following year the 2nd Division Concert Party, and with which he toured Australia, New Guinea and New Britain as both producer and comedian.
After the war Wallace turned to the professional stage. He toured his own revue companies and spent almost a decade at the Theatre Royal, Brisbane. 'His four thousand or so performances at the Royal in revue and pantomime in one straight run were considered at the time to be 'easily a world record for a comedian,' writes Raymond Evans. Wallace began working in television in 1959, performing on such variety shows as Curtain Call (ATN-7) and Joe Martin's The Late Show (TCN-9). Although he found the new medium difficult to begin, some guidance from veteran vaudeville comedian and producer led to TCN-9 giving him his own show in 1960. The following year he returned to Brisbane to host his Logie Award-winning variety show Theatre Royal. He remained at the helm until his death in 1968. Wallace reportedly wrote more than 2,500 comedy sketches during his television career.