Ginty was born in Brooklyn, New York, the son of Elsie M. (née O’Hara), a government worker, and Michael Joseph Ginty, a construction worker. Ginty was involved with music from an early age, playing with Jimi Hendrix, Janis Joplin, Carlos Santana and John Lee Hooker. He studied at Yale and trained at the Neighborhood Playhouse and the Actors Studio. Ginty worked in the regional theater circuit, and New York theatre Broadway. Harold Prince hired him as his assistant after seeing him perform in The New Hampshire Shakespeare Festival Summerstock Company under the direction of Jon Ogden 1973. Ginty moved to California in the 1970s, where he found frequent work as a strong-armed player on television action, appearing in different series in the mid-1970s. In 1975, he appeared in the NBC television movie John O’Hara’s Gibbsville (also known as The Turning Point of Jim Malloy). In 1976, he attained some popularity after finding a steady role starring with Robert Conrad in Baa Baa Black Sheep, a successful television series about the experiences of United States Marine Corps aviator Pappy Boyington and his squadron of misfits during World War II. Ginty had small parts in Bound for Glory (1976) and Two-Minute Warning (1976). He later made his biggest impression as Bruce Dern’s friend in Coming Home (1978). He had guest appearances in the first couple of seasons on Simon & Simon, as A.J. and Rick’s medical examiner friend on the police force. He then went on to co-star in three television series: The Paper Chase (1978) (where he met future wife Francine Tacker), Falcon Crest and Hawaiian Heat. He also appeared in John Llewellyn Moxey’s The Courage and the Passion.

Ginty made his first appearance on film in the late 1970s in two Hal Ashby movies. He then starred with David Carradine in the 1976 Bound for Glory biography of folk singer Woody Guthrie. He also appeared with Bruce Dern in Coming Home (1978) (a film which was nominated for eight Oscars). Around the time he was appearing in the series The Paper Chase (1978), he won his first film action lead in The Exterminator (1980), which became a surprising box-office hit. Ginty’s acting career faded in the 1990s, although he played some higher-quality roles, such as in Tom Ropelewski’s comedy Madhouse. Ginty also performed in another big production, with Mickey Rourke and Don Johnson, in Harley Davidson and the Marlboro Man. He became an independent producer/director, and formed his own production company, where he became the head of the company, Ginty Films, buying shares in the special effect studio Introvision that distributed his vehicles both here and abroad. Most were crudely made on very limited budgets, but he had nevertheless done quite well for himself as a writer/producer/director, especially overseas, with such assembly-line fare as Gold Raiders (1983) which was filmed in Thailand, Cop Target (1990), which was shot in France. He did not slow down in the late 1990s, performing producing and directing chores on such shows as China Beach (1988), Xena: Warrior Princess (1995), Nash Bridges (1996), Charmed (1998) and Tracker (2001). Ginty resided, variously, in Los Angeles, Dublin, Toronto, and Vancouver. He was married to actress and former co-star Francine Tacker; they had a son, actor James Francis Ginty. Ginty had also been married to actress Lorna Patterson. (Both Tacker and Patterson would work together in the short-lived situation comedy Goodtime Girls) He was married to his third wife, Michelle Craske, at the time of his death of cancer in Los Angeles, California.