Ornithocephalus aristatus, a new species from Panama, is described and illustrated. Among the species of the genus Ornithocephalus, it can be distinguished by the nonresupinate flowers, the sepals each provided with a flexuous awn half as long as the sepal itself, the porrect petals with revolute margins, the hastate lip with triangularovate, erose lateral lobes, the linear, acute midlobe, conduplicate and subreflexed at apex, and the disc with a bilobed, obreniform callus provided with a conical tuft of stiff hairs. A key to the species of Ornithocephalus from Panama is provided.