Kilbourne Hole is a maar volcanic crater, located 30 miles (48 km) west of the Franklin Mountains of El Paso, Texas, in the Potrillo volcanic field of Doña Ana County, New Mexico. Another maar, Hunt's Hole, lies just two miles south of Kilbourne Hole. These holes are rare examples of volcanic action without a mountainous rim.

The theory of maar formation is that rising magma super-heats water-saturated earth, far enough below the surface that a high pressure can be contained. At some point, the pressure is too much, and a steam explosion occurs, throwing the earth out in a catastrophic event.Country rocks are fragmented and expelled in the atmosphere (together with fragments of the magma), eventually creating a deep crater, the bottom of which sits below the pre-eruptive ground surface.

Estimates of the age of the crater vary from about 24,000 to about 80,000 years.

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