Gertie the Dinosaur is a 1914 animated short film by American cartoonist and animator Winsor McCay. It is the earliest animated film to feature a dinosaur. McCay first used the film before live audiences as an interactive part of his vaudeville act; the frisky, childlike Gertie did tricks at the command of her master. McCay's employer William Randolph Hearst curtailed McCay's vaudeville activities, so McCay added a live-action introductory sequence to the film for its theatrical release renamed Winsor McCay, the Famous Cartoonist, and Gertie. McCay abandoned a sequel, Gertie on Tour (c. 1921), after producing about a minute of footage.

Although Gertie is popularly thought to be the earliest animated film, McCay had earlier made Little Nemo (1911) and How a Mosquito Operates (1912). The American J. Stuart Blackton and the French Émile Cohl had experimented with animation even earlier; Gertie being a character with an appealing personality distinguished McCay's film from these earlier "trick films". Gertie was the first film to use animation techniques such as keyframes, registration marks, tracing paper, the Mutoscope action viewer, and animation loops. It influenced the next generation of animators such as the Fleischer brothers, Otto Messmer, Paul Terry, Walter Lantz, and Walt Disney. John Randolph Bray unsuccessfully tried to patent many of McCay's animation techniques and is said to have been behind a plagiarized version of Gertie that appeared a year or two after the original. Gertie is the best preserved of McCay's films—some of which have been lost or survive only in fragments—and has been preserved in the U.S. Library of Congress' National Film Registry as being "culturally, historically, or aesthetically significant" since 1991.

In 1994, Gertie the Dinosaur was voted #6 of the 50 Greatest Cartoons of all time by members of the animation field.