Lazarus Long is a fictional character featured in a number of science fiction novels by Robert A. Heinlein. Born in 1912 in the third generation of a long-life selective breeding experiment run by the Ira Howard Foundation, Lazarus (whose birth name is Woodrow Wilson Smith) turns out to be unusually long-lived indeed, living well over two thousand years with the aid of occasional rejuvenation treatments.

A rugged individualist with a distrust of authority, Lazarus drifts from colony world to colony world, settling down for a few years or a few decades and leaving when things get too regimented for his taste—often just before the angry mob arrives.