The Cloudless Sulphur (Phoebis sennae) is a small to midsized butterfly in the family Pieridae found in the New World. There are several similar species such as the Yellow Angled Sulphur which has angled wings or other sulphurs which are much smaller.

Their range is wide, from South America to southern Canada. They are most common from Argentina to southern Texas and Florida, but are often visitors outside this range becoming more rare further north.