Robert Allman was born in Melbourne in 1927. He studied in Paris and sang at the Royal Opera, Covent Garden for three seasons from 1955. He then moved to Germany, where he sang in over a dozen opera houses. He also sang in opera houses including Zurich, New Orleans, Singapore and Vienna.
He then became a Principal Artist with Opera Australia, where he remained for the rest of his career. He sang in eleven roles alongside Sutherland. His repertoire included the core bass-baritone roles of Rigoletto, Gianni Schicchi, Macbeth, The Flying Dutchman and Simon Boccanegra. He also sang as Don Fernando and Pizarro in Fidelio, Rangoni in Boris Godunov, Valentine in Faust, Wolfram in Tannhäuser, Donner in Das Rheingold, Telramund in Lohengrin, Kothner in Die Meistersinger von Nürnberg, the four villain roles in The Tales of Hoffmann, Anckarstroem in Un ballo in maschera, Amonasro in Aida, Iago in Otello, Germont in La traviata, Sharpless in Madama Butterfly, Tonio in Pagliacci, Marcello in La bohème and Scarpia in Tosca.
His death was announced on 4 December 2013.