LDD may refer to:
- 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) is a *nix utility that List Dynamic Dependencies.
- Living Dead Dolls
- Liquid Detainment Device, a box shaped machine designed to drain excess liquid in recyclable bottles and encourage people to remove the bottle caps. Created and patented by Gunnar Engineering
ldd (List Dynamic Dependencies) is a *nix utility that prints the shared libraries required by each program or shared library specified on the command line. It was developed by Roland McGrath and Ulrich Drepper. ldd is a shell script that executes the program given as argument, and shouldn't be used with untrusted binaries. If some shared library is missing for any program, that program won't come up.