Smilodon, more commonly known as "Saber-Toothed Tiger" or "Saber-Toothed Cat", is a large felid that was native throughout the Americas during both the Pleistocene and Holocene. Smilodon is famous for its large fangs and muscular build.

Smilodon was named in 1842 by Peter Wilhelm Lund, and its name means "Knife Tooth". The original material was at first thought to belong to a hyena by Lund, but as more pieces of the animal became known to him, he recognized it as belonging to a felid. He considered naming the animal Hyaenodon due to his original identification of the animal, but the name was taken by the current creodontan holder of the name, so Lund instead named his animal Smilodon populator, "The Knife Toothed Destroyer".

Smilodon fatalis was found independently and assigned by Joseph Leidy in 1869 to the genus Felis as "Felis fatalis" as it was customary at the time for many cats both living and dead to be lumped into this genus. It was later in an 1880 article on American extinct cats that Edward Drinker Cope of Bone Wars fame pointed out the near identical nature of "Felis fatalis" and Smilodon populator and proposed a combination of the two into the current Smilodon fatalis, "The Fatal Knife Tooth".