D. or d. may refer to, usually as an abbreviation: * Don (honorific), a form of address in Spain, Portugal, Italy, and their former overseas empires, usually given to nobles or other individuals of high social rank. * Date of death, as an abbreviation. * District of Columbia Department of Transportation, whose logo is "d." * ''Schubert Thematic Catalogue'', also known as the Deutsch catalogue (or D.), a numbered list of all compositions by Franz Schubert compiled by Otto Erich Deutsch. * a penny, from the Latin ''denarius''.

See also