Gary Onik (born February 25, 1952, in Brooklyn, New York City) is a medical doctor and inventor. He is known for ultrasound-guided procedures for treating cancer using cryosurgery.
Gary Onik is the inventor of ultrasound-guided cryosurgery procedures for the prostate and for the liver.
Onik treated the first liver patients with cryosurgery in 1986 and the first patient with ultrasound-guided prostate cancer cryosurgery in 1990. He developed techniques and instrumentation that have been integral to the minimally invasive treatment of cancer.