Phidippus regius (commonly called the Regal Jumping Spider) is a species of jumping spider. It is the largest jumping spider in eastern North America, with adult males averaging 12 millimetres (0.47 in) in length (ranging from 6–18 millimetres (0.24–0.71 in)), and females averaging 15 millimetres (0.59 in) (ranging from 7–22 millimetres (0.28–0.87 in)).
Males and females are easily differentiated. The males are always black with a pattern of white spots and stripes. Females often bear similar patterns to the males, but range in color from shades of gray to a vivid orange.
The Regal Jumping Spider belongs to the genus Phidippus, a group of jumping spiders easily identified both by their relatively large size and their iridescent chelicerae. Among most members of Phidippus, these chelicerae are generally green, but in the case of P. regius they are often a blue-violet.
P. regius is most commonly found in relatively open areas, such as fields and light woodland, with adults usually preferring trees or the walls of buildings as hunting grounds. They build silken nests at night in which to sleep, often in palm fronds or similar areas. Females of the species lay their eggs under the bark of trees, or in secluded spots in wooden structures such as barns.