Dorsum Cayeux is a wrinkle ridge at 1°36′N 51°12′E / 1.6°N 51.2°E / 1.6; 51.2 in Mare Fecunditatis on the Moon. It is approximately 95 km long and was named after French geologist Lucien Cayeux in 1976 by the IAU.^[1]

Dorsum Cayeux begins on the north side of Taruntius P crater and trends to the northwest past Taruntius K crater, and then it curves back to the northeast and flattens out into the mare surface northwest of Smithson crater. The ridge is probably a continuation of Dorsa Geikie, which ends on the south side of Taruntius P crater (i.e., the object that created Taruntius P impacted the ridge).