Sean Patrick Astin (né Duke; February 25, 1971) is an American actor, voice actor, director and producer. He is best known for his roles as Samwise Gamgee in The Lord of the Rings trilogy (2001–2003), Mikey Walsh in The Goonies (1985), the title character of Rudy (1993), Doug in 50 First Dates (2004), and Bob Newby in the second season of Stranger Things (2017).
Astin was born in Santa Monica, California, the son of actress Patty Duke (1946–2016). At the time, it was erroneously reported that entertainer Desi Arnaz Jr. was his biological father. When Michael Tell, a writer, music promoter and publisher of the newspaper The Las Vegas Israelite, came to sublet her apartment and offered to marry her as a way out of the scandal, Duke agreed. The marriage lasted only 13 days in 1970, and ended long before Astin was born.
On August 5, 1972, Duke married actor John Astin, after having been in a relationship with him for two years. When the wedding guests were invited to speak, 18-month-old Astin looked at John and cried, "Daddy!", to which the Episcopal priest performing the ceremony remarked, "Well, that about does it!" Astin subsequently adopted Sean. In 1973, Duke gave birth to Astin's brother, Mackenzie Astin, who also became an actor. Duke and John Astin divorced in 1985. Duke married Mike Pearce in 1986, and they adopted a son, Kevin, in 1989.