APD may refer to:
Medicine
- Acid peptic diseases
- Afferent pupillary defect
- Antimicrobial Peptide Database
- Antipsychotic drug
- Antisocial personality disorder
- Auditory processing disorder
- Autoimmune progesterone dermatitis
- Automated peritoneal dialysis
- Avoidant personality disorder
- Pamidronic acid
Police departments
- Airport Police Division, Singapore
- Akron Police Department, Ohio, United States
- Albuquerque Police Department, New Mexico, United States
- Amtrak Police Department, United States
- Anchorage Police Department, Alaska, United States
- Annapolis Police Department, Maryland, United States
- Antioch Police Department, California, United States
- Apopka Police Department, Florida, United States
- Arcadia Police Department, California, United States
- Atlanta Police Department, Georgia, United States
- Aurora Police Department, Colorado, United States
- Austin Police Department, Texas, United States
Transport
- Air Passenger Duty, an excise duty levied on passengers flying from UK airports
- Albany Port Railroad, United States
- APD-40, a highway in Tennessee, United States
- Appledore (Kent) railway station, United Kingdom
Other uses
- Air Products & Chemicals, an American industrial gas and chemical company
- Alliance for Democracy (Dominican Republic) (), a Dominican Republic political party
- Alpha Phi Delta, an American college fraternity
- American political development
- Apple Accessory Products Division, now The Keyboard Company
- Avalanche photodiode
- High-speed transport, in the United States Navy
- Peace Through Law Association (, a French pacifist organisation
- Sudanese Arabic, a variety of the Arabic language