6D, 6d, or 6-D may refer to:
Canon EOS 6D, a digital SLR camera Jamaica 6d abolition of slavery postage stamp, a 1921 stamp issue Six-dimensional space, any space that has six dimensions 6D, the production code for the 1983 Doctor Who serial Snakedance Sixpence (British coin), often shortened to "6d."
Aircraft Boeing Model 6D, an American biplane flying-boat B-6D, a model of Xian H-6 Grumman KA-6D, a model of Grumman A-6 Intruder F-6D Mustang, a model of North American P-51 Mustang North American AT-6D Texan, a model of North American T-6 Texan OH-6D, a model of Hughes OH-6 Cayuse XP-6D, a model of Curtiss P-6 Hawk
See also Sixpence (disambiguation) D6 (disambiguation)