Parajulidae is a family of millipedes in the order Julida, occurring predominantly in North America but also in Central America and East Asia. Parajulids occur in Alaska, and the continental United States as well as bordering Canadian provinces, and as far south as Guatemala. Male Parajulids have a greatly enlarged first pair of legs, and externally exposed gonopods, in contrast to the largely Eurasian family Julidae which have a small, hook-shaped first pair of legs, and gonopods concealed internally.