Spelling variations include Cullen, Cullan, Cullane, O'Cullen, Cullain, Cullin, Cullon, McCullen, MacCullen, O'Cullane, Culen, Culan, Culain, Cullaine, Culaine, MacCulen, MacCollin, MacColin, O'Colen, O'Collen, O'Cuilin, O'Cuillin, O'Culane, O'Culen, O'Culhoon, O'Culloon, MacCullen, Cullain, Culon, Cullon, Culling and many more.