Damon Runyon (4 October 1884 – 10 December 1946) was a newspaperman and writer.

He was best known for his short stories celebrating the world of Broadway in New York City that grew out of the Prohibition era. He spun humorous tales of gamblers, hustlers, actors, and gangsters; few of whom go by "square" names, preferring instead to be known as "Nathan Detroit," "Big Jule," "Harry the Horse," "Good Time Charley," "Dave the Dude," and so on. These stories were written in a very distinctive vernacular style: a mixture of formal speech and colorful slang, almost always in present tense, and always devoid of contractions.

Here is an example from the story Tobias the Terrible, collected in More than Somewhat (1937): If I have all the tears that are shed on Broadway by guys in love, I will have enough salt water to start an opposition ocean to the Atlantic and Pacific, with enough left over to run the Great Salt Lake out of business. But I wish to say I never shed any of these tears personally, because I am never in love, and furthermore, barring a bad break, I never expect to be in love, for the way I look at it love is strictly the old phedinkus, and I tell the little guy as much.

To New Yorkers of his generation, a "Damon Runyon character" evoked a distinctive social type from the Brooklyn or Midtown demi-monde. The adjective "Runyonesque" refers to this type of character as well as to the type of situations and dialog that Runyon depicted.

The musical Guys and Dolls was based on two Runyon stories, "The Idyll of Miss Sarah Brown" and "Blood Pressure"; the play Little Miss Marker grew from his short story of the same name.

Runyon was also a newspaperman. He wrote the lead article for United Press on Franklin Delano Roosevelt's inauguration in 1933.