John Drew Barrymore, was born as John Blyth Barrymore, Jr. (June 4, 1929 in Beverly Hills, California – November 29, 2004 in Los Angeles) was a member of The Barrymore family of actors that included his father, John Barrymore, and his father's siblings, Lionel and Ethel. He was the father of 4 children, including John Blyth Barrymore and Drew Barrymore.

His mother was Dolores Costello. His parents divorced when John was around 6 years old in 1935, but he claimed (most likely fallaciously) to have met his father only once.

John and his cousin, Dirk Drew Davenport, enlisted in the US Navy during World War II. Due to their physical appearance, the military did not discover until several weeks later that the boys were underage. John ran away at age 17 and signed a film contract, but he repeatedly abandoned leading roles and had no major film career.

In 1958, he changed his name to John Drew Barrymore and had a brief resurgence in film, appearing in several leading roles. However, his social behavior obstructed any professional progress. In the 1960s, he was occasionally incarcerated due to drug activity, public drunkenness, and spousal abuse.

He married four times, each marriage produced one child, and all four marriages ended in divorce:

1. Cara Williams: married 1952, divorced 1959; son John Blyth Barrymore#Gabriella Palazzoli: married October 11, 1960, divorced 19??; daughter Blyth Dolores Barrymore#Ildiko Jaid Mako: married 19??, divorced 1977; daughter Drew Barrymore#Nina Wayne: married 19??, divorced 19??; daughter Jessica Barrymore

In the late 1960s, John Drew accepted a major guest role as Lazarus in the Star Trek episode "The Alternative Factor". He failed to show up (and was ultimately replaced at the last minute by actor Robert Brown), resulting in SAG suspending Barrymore for six months.

Although he continued to appear occasionally onscreen, he became more and more reclusive. Suffering from the same problems which had destroyed his father, John Drew became a derelict. Estranged from his family, including his children, his lifestyle continued to worsen and his physical and mental health suffered. In 2003, Drew moved him near her home despite their estrangement, paying his medical bills until his death from cancer.

He has a star on the Hollywood Walk of Fame for his contributions to television.