  Near-Earth asteroid population models predict the existence of bodies located
inside the orbit of Venus. Despite searches up to the end of 2019, none had
been found. We report discovery and follow-up observations of (594913)
'Ayl\'o'chaxnim, an asteroid with an orbit entirely interior to Venus. (594913)
'Ayl\'o'chaxnim has an aphelion distance of ~0.65 au, is ~2 km in diameter and
is red in colour. The detection of such a large asteroid inside the orbit of
Venus is surprising given their rarity according to near-Earth asteroid
population models. As the first officially numbered and named asteroid located
entirely within the orbit of Venus, we propose that the class of interior to
Venus asteroids be referred to as 'Ayl\'o'chaxnim asteroids.
