LDD may refer to:
- Learning difficulties and disabilities (UK)
- Lego Digital Designer, a CAD software application for designing Lego models
- Lhermitte–Duclos disease, a rare, slowly growing tumor of the cerebellum
- Libertarian, Direct, Democratic, a Belgian political party
- Lidhja Demokratike e Dardanisë (English: Democratic League of Dardania), a political party in Kosovo
- Local development document, a set of documents specified in United Kingdom planning law
- Local Dialing Disparity
- Lycée Denis Diderot (Kenya), a French international school in Nairobi, Kenya
- Lightly Doped Drain, a sub-structure in a MOSFET that is intended to permit operation with higher drain-source voltage
- Long Distance Dedication, a feature on the weekly syndicated radio program American Top 40
- ldd (Unix), a utility to List Dynamic Dependencies
- Living Dead Dolls
- Lymantria dispar dispar, a species of moth (gypsy moth)