R2-D2 (phonetically spelled Artoo-Detoo, and called "R2" or "Artoo" for short) is a robot character in the Star Wars universe. An astromech droid (referred to in the novel as a 'thermocapsulary dehousing assister'), R2-D2 is a major character in all six Star Wars films. Along with his protocol droid companion C-3PO, he joins or supports Anakin Skywalker, Luke Skywalker, Princess Leia, and Obi-Wan Kenobi in various points in the saga. R2-D2 was played by Kenny Baker. Along with Anakin Skywalker (Darth Vader), Obi-Wan Kenobi, and C-3PO, he is one of only four characters to appear in all six Star Wars films.

R2-D2 was designed by John Stears and Tony Dyson specially created by Australian firm Petric Engineering and English firm C&L Developments. Many scenes also made use of radio controlled and CGI versions of the character. Both the original props of R2-D2 and C-3PO used in filming are used as audio-animatronics in the queue area of Disneyland's Star Tours ride.