LDU may refer to:
Politics Alliance of Independents (), a 1936–1999 political party in Switzerland Lahu Democratic Union, a political and insurgent group in Myanmar Liberal and Democratic Union, a 1906–1910 South Australian political party National Self-Government of Germans in Hungary ()
Science and mathematics Land disposal unit, a term in bioremediation LDU decomposition, a factorization of matrices found in linear algebra Linear Drive Unit, a type of orbital replacement unit used on the International Space Station
Other uses Lahad Datu Airport (IATA code), Sabah, Malaysia Lawrence Debate Union, the official debate team of the University of Vermont Liga Deportiva Universitaria (disambiguation), several Ecuadorian football clubs Local Delivery Unit, last three digits of a Canadian postal code Luke Davies-Uniacke (born 1999), Australian rules footballer