Luidia ciliaris, the seven-armed sea star, is a species of sea star (starfish) in the family Luidiidae. It is found in the eastern Atlantic Ocean and the Mediterranean Sea.

Description L. ciliaris is an orangeish-brown colour and has seven long arms radiating from a small disk. It is a large but fragile sea star, growing to 40 cm (16 in) across, and easily losing its arms (which afterwards regenerate). The arms have parallel sides and taper only near the tip. They have a conspicuous fringe of white spines along the margins. The upper surface is clothed in paxillae, spines shaped like a pillar with a flat top bearing tiny spinules. Also, many-lobed, nipple-like papillae are seen. No marginal plates are on the upper side of the arms, but those on the lower side bear pedicellariae with two valves. The tube feet are long and numerous.