UDD may refer to:

Science and technology

*deuterium, Ultra-dense deuterium *Neutrons, which have quark configurations of udd, or up quark, up-down quark, down-down *Ultradisperse diamond, another name for Detonation nanodiamond *Urine-diverting dry toilet, Urine-diversion dehydration toilet *User-centered design, User driven development

Others

*Actuarial notation#Life tables, Uniform Distribution of Deaths, an assumption used in building actuarial life tables *Bermuda Dunes Airport *UDD, the station code for the Uddingston railway station in Uddingston, Scotland *United Front for Democracy Against Dictatorship, a political movement in Thailand *Universidad del Desarrollo private university in Chile *Up dharma Down, a Filipino band {{disambiguation