Liberty cap most often refers to: Phrygian cap or pileus (hat), emblematic of a slave's manumission in classical antiquity Liberty cap may also refer to: Liberty Cap (California), a granite dome in Yosemite National Park Liberty Cap, a prominent peak on Mount Rainier Liberty cap (Psilocybe semilanceata), a psilocybin mushroom Liberty Cap half cent, an early coin of the United States dollar Liberty Cap large cent, an early coin of the United States dollar