Eurema proterpia, the tailed orange, is a North and South American butterfly in the family Pieridae.

The upperside of the wings is orange with a variable amount of black along the forewing costa.

Males reflect UV light on their upper sides, and some females can be white.

Summer individuals are yellow orange with the hindwing slightly pointed.

[2][3] This species may be found from mid-July to early January in Arizona, from August to November in Texas, and all year round in Mexico.