Julian Dana William McMahon was born in Sydney, Australia, the second of three children of Lady Sonia McMahon (née Sonia Rachel Hopkins) and Sir Billy McMahon, the longest continuously serving government minister in Australian history, serving over 21 years as a government minister before serving as Prime Minister of Australia from March 1971 to December 1972.
McMahon won recognition for his portrayals in American television dramas, such as Detective John Grant in the crime drama Profiler (1996–2000), Cole Turner in the supernatural drama Charmed (2000–2003) and Dr. Christian Troy in the medical drama Nip/Tuck (2003–2010). He also appeared in films with leading and supporting roles, such as Chasing Sleep (2000) alongside Jeff Daniels, Doctor Doom in the Fantastic Four duology (2005 and 2007), Premonition (2007) alongside Sandra Bullock, Red (2010) alongside Bruce Willis, Faces in the Crowd (2011) alongside Milla Jovovich, and Bait 3D (2012) alongside Sharni Vinson and Phoebe Tonkin. For his performance in Nip/Tuck, McMahon was nominated for the Golden Globe for Best Actor in a Television Drama Series.
McMahon died from lung metastasis caused by head and neck cancer, in Clearwater, Florida. He had not disclosed his diagnosis publicly. His remains were quietly cremated.
