Elf is an available species in D&D. In the world of the Order of the Stick, most elves live in the 'Elven Lands', a portion of the Western Continent. Elves can breed with humans, the result is a half-elf. Known elves include Vaarsuvius, Inkyrius and Aarindarius.
Most elves in the world the Order of the Stick have genders that are ambiguous both to readers and to non-elven characters. The sole exception to date is Lirian, who is clearly female.