A third-generation Los Angeles native, he graduated from the University of Michigan with a degree in law. For about seventeen years, McCarthy was associated with businessman Howard Hughes as his attorney and was a vice president in the Hughes organization during World War II.^[1] McCarthy set up practice in Los Angeles where he rose to fame as an attorney for many in the film industry. Among his clients were Paramount Pictures and well-known personalities such as producer Cecil B. DeMille, MGM Studios boss Louis B. Mayer, and actors Ginger Rogers, Joan Bennett, Betsey Cushing Roosevelt, Joan Crawford, Lana Turner, and Ava Gardner.^[2]

Neil McCarthy and his wife Marguerite had four children. A daughter, Marjorie, married Dennis J. Gless and were the parents of actress Sharon Gless. She sought her grandfather's advice and he told her: "It's a filthy business. You stay out of it" but a few years later when she spoke to him again about acting, he encouraged her, and gave her money for acting classes.^[3] Another daughter, Rosemary, married Dr. John A. E. Bullis. In 1975, Rosemary Bullis was awarded a Silver Cup for Outstanding Achievement by the Los Angeles Times as one of its ten "Women of the Year."^[4] In 1966 Marguerite McCarthy died ^[5] and in 1969 Neil McCarthy remarried artist Mary Beich Myers.^{[citation needed]}

A polo player, Neil McCarthy was a member of the Midwick Country Club and captain of its polo team.^[6]

The Neil McCarthy salad,^[7][8] named in his honor, remains a signature dish tossed tableside at the Polo Lounge in Beverly Hills. The Blvd. restaurant at the Beverly Wilshire Hotel also serves a Neil McCarthy tossed salad.^[9]

In addition to a home in Beverly Hills, McCarthy owned a horse ranch in Hidden Valley. His involvement with horses extended to California Thoroughbred horse racing, both as an owner and as a breeder. In January 1948, he purchased the great Australian runner, Shannon.^[10] The horse won a number of important races for him in California, including the prestigious Hollywood Gold Cup. Shannon would be voted a share of 1948 American Champion Older Male Horse honors. After retiring him from racing, McCarthy sold the horse to a breeding syndicate headed by Leslie Combs II of Lexington, Kentucky, but kept a share of the breeding rights for himself.^[11]

Among his other racing successes, McCarthy won the 1959 Bing Crosby and Palos Verdes Handicaps, plus the San Vicente Stakes with Ole Fols, a horse he purchased in Ireland. In 1962, his colt Royal Attack won California's most important race for three-year-olds, the Santa Anita Derby.

Following a stroke, 84-year-old McCarthy died on July 25, 1972, in Good Samaritan Hospital in Los Angeles.^[12][13]