Rosemary Lassig , known after marriage as Rosemary Lluka, was an Australian breaststroke swimmer of the 1960s, who won a silver medal in the 4×100-metre medley relay at the 1960 Summer Olympics in Rome. Lassig combined with Dawn Fraser, Jan Andrew and Marilyn Wilson to register a silver medal in the 4×100-metre medley relay five seconds behind the winners, the United States. In her only individual event, the 200-metre breaststroke, she did not advance beyond the preliminary heats.