On 25th of November 1961, Robert got married to Sondra Blake. Sondra Blake is also an actress. She is known for her appearance in the movies like Helter Skelter, Portend and The Killer Elite. As a married couple, they became parents twice. This happy married life was dissolved on 12th of September 1983.
In 1999, Robert fell in love with Bonnie Lee Bakley. Bonnie was known for exploiting older men for money. From this romantic love life she became pregnant but during that time she was also dating Christian Brando. After the DNA test, Robert was proved to be the biological father of her child and then they got married on 15th of November 2000. However, she was shot dead on 4th of May 2001 and he was accused of this murder.
Robert struggled a lot as a child. He was physically and sexually abused by his parents. He made his acting debut in 1939 starring the role of Annabella and Robert Young in the movie, Bridal Suite. He also appeared in the TV series, Our Gang short subjects. In 1942, he appeared in the movie Andy Hardy's Double Life. He also served in the US Army for several years. His net worth is said to be in millions.