- D4D stands for Dogs for Diabetics (Concord, CA)
- D4D stands for Drive for Diversity (National Association for Stock Car Auto Racing)
- D4D stands for Dynamics for Display (various locations)
- D4D stands for Downtown for Democracy (New York)
- D4D stands for Design for Demise (space debris)
- D4D stands for Devices for Dignity (healthcare technology cooperative; UK)
- D4D stands for Designing for Dissemination (US NCI; Bethesda, MD)
- D4D stands for Dollars for Democrats (political group)
D4D