Elongated Man (Randolph William "Ralph" Dibny) is a superhero appearing in American comic books published by DC Comics. He first appeared in The Flash #112 (February 25, 1960).

The character made his live-action debut on The CW's live-action Arrowverse television series The Flash, portrayed by Hartley Sawyer. Additionally, Jeremy Piven, Sean Donnellan, and David Kaye have voiced the character in animation.

Elongated Man was created by writer John Broome and penciler Carmine Infantino, with significant input from editor Julius Schwartz, who wanted a new supporting character for the Flash. Schwartz has noted that Elongated Man was only created because he had not realized that Plastic Man was available due to DC obtaining the rights to him in 1956 alongside other Quality Comics properties. However, Infantino and inker Murphy Anderson stated that they never used Plastic Man as a reference.

In his 2000 autobiography, The Amazing World of Carmine Infantino, the artist wrote, "I really liked Elongated Man because it was comical and I enjoyed drawing comedy. It was also one of my favorite strips, because it was as close to animation as I could do in a comic book. I liked being able to test the limits of the comic book form and this strip allowed me to do that."

Elongated Man received a solo backup feature in Detective Comics, where he was redefined as a detective who loves odd mysteries and travels the United States in a convertible with his wife, searching for them. Sometimes they would travel the world or meet other DC superheroes like Batman, Green Lantern, the Atom and Zatanna. This feature became sporadic during the late '60s and throughout the '70s. However, in 1973, he became a member of the Justice League of America, and he is mostly seen in that title from 1973 to 1995.

As a teenager, Ralph Dibny was fascinated by contortionists, or people who displayed feats of agility and suppleness. He learned that all of the body-benders he spoke with drank a popular soda called "Gingold". Ralph set to work learning chemistry and developed a super-concentrated extract of the rare "gingo" fruit of the Yucatán, which gave him his elasticity. In his first appearance, the Flash suspects Elongated Man is behind several crimes, but he helps capture the criminals, who reveal they used a helicopter to frame him.

Ralph Dibny was one of the earliest Silver Age DC heroes to reveal his secret identity to the public, and also one of the first to marry his love interest. After teaming up with several other superheroes like Batman, Green Lantern, the Atom, Zatanna and the Justice League, he became a member of the team. Eventually, his wife Sue Dibny became a member as well. The couple was also notable in having a stable, happy, and relatively trouble-free marriage—an anomaly in the soap operatic annals of superhero comic books.

Ralph Dibny played a central role in the events of Identity Crisis, with the main arc of the series revolving around Sue Dibny being murdered. The two's relationship, and the events that led to and resulted from her death, were used as primary narrative devices throughout the series for examining the respective personal relationships of other JLA and JSA members.