UDP may refer to:

in political parties:

  • United Democratic Party, one of multiple organizations
  • Ulster Democratic Party, in Northern Ireland
  • Democratic and Popular Union (Spanish: Unidad Democrática y Popular) a former Bolivian umbrella party
  • People's Democratic Union (Portugal)

on the Internet:

  • User Datagram Protocol, a network communications method
  • Usenet Death Penalty, a discussion group disciplinary response

in other uses:

  • Unit Deployment Program, a military assignment system
  • Unitary development plan, a land use planning system
  • Uridine diphosphate, an organic chemical
  • Diego Portales University, a school