Narceus is a genus of large cylindrical millipedes of the family Spirobolidae native to eastern North America. The genus comprises three or four species, two of which are endemic to Florida, and the remainder forming a species complex. The species of Narceus include some of the largest and most recognizable millipedes in eastern North America.

Narceus individuals range from 4 to 12 cm long, with 45 to 59 segments as adults. Their body color is various shades of brown with reddish to yellow stripes on each segment.