A PDA may stand for:
Personal Digital Assistant, a digital device which can include the functionality of a computer, a cellphone, a music player and a camera.
Pitch Detection Algorithm, a mathematical method of finding the pitch of a signal.
Public Display of Affection, an area of study within social psychology.
Patent Ductus Arteriosus, a congenital heart defect.
Push-Down Automaton, a type of abstract device in automata theory.
Progressive Democratic Alliance, an historical political party in British Columbia, Canada.
Progressive Democrats of America, a political organization in the United States.
Past Doctor Adventures, a series of spin-off novels based on Doctor Who
Phase-Doppler Analyzer, a kind of instrument for measure particle volecity and size.
Polo Democratico Alternativo, (Alternative Democatic Pole), a political party in Colombia.
Private Defense Agency.
Posterior Descending Artery, one of the coronary arteries
Panic Disorder with Agoraphobia.
Perception-Decision-Action, a model of cognition,
PDA is also a song by the band Interpol