Callville Wash is an ephemeral stream or wash in Clark County, Nevada. It was named for Callville the riverport settlement founded in 1866, at its mouth where it had its original confluence with the Colorado River.
Its mouth is at its confluence with Callville Bay, at an elevation of 1,234 feet / 376 meters when Lake Mead is at its full level. Currently as the reservoir is at a much lower level its mouth is found at approximately 36°08′3″N 114°42′38″W / 36.13417°N 114.71056°W. Its source is located at an elevation of 3,510 feet / 1,070 meters at 36°16′35″N 114°41′00″W / 36.27639°N 114.68333°W on the southern slope of Muddy Peak (5387 ft / 1642 m) in the Muddy Mountains.
Callville Wash originally had a tributary, originally known as West Fork Callville Wash, whose confluence with Callville Wash is now under Callville Bay. Following the creation of Lake Mead it now flows into Callville Bay, at 36°08′24″N 114°42′57″W / 36.14000°N 114.71583°W and is known as West End Wash.