Dennis Bruce Allen (7 November 1951 – 13 April 1987) was a notorious Australian drug dealer and alleged serial killer based in Melbourne. He was the oldest son of Kath Pettingill, a criminal matriarch. Allen's lawyer, Andrew Fraser, helped him avoid jail time by leveraging his knowledge of corrupt Victorian police officers at the time. However, Allen died of heart disease in 1987 while in prison custody, awaiting trial for murder.