After his last season with D'Oyly Carte, Walker and Roberts were engaged by the J. C. Williamson Gilbert and Sullivan Opera Company, and toured Australia and New Zealand throughout the 1950s and early 1960s. When the Williamsons played Gilbert and Sullivan, as they did for extended tours every five or six years, Walker sang his familiar roles, as well as Dick Deadeye in "Pinafore" and Sergeant Meryll in "Yeomen", and he directed the operas. Walker and Roberts also performed in musical comedies in Australia under other management. From 1959, they toured for more than four years in the original Australian production of "My Fair Lady", Walker as Alfred P. Doolittle and Roberts as Mrs. Eynsford-Hill. They then settled in Sydney. Walker later appeared in the Williamson production of "A Funny Thing Happened on the Way to the Forum". In 1967, he joined the Elizabethan Theatre Company, playing Frosch in "Die Fledermaus".