| AP | Andhra Pradesh (India) | |
| AP | Apartment | |
| A/P | All Purpose (various companies) | |
|
| AP | Airplane | |
| AP | Associated Press | |
| AP | Advanced Placement | |
| AP | Air Pollution | |
| AP | Armed Forces Pacific | |
| AP | Accredited Professional | |
| A/P | Airport | |
| AP | Access Point | |
| AP | Access Port | |
| AP | Assistant Principal | |
|
| AP | Transport | |
| AP | Asia Pacific | |
| AP | Anatomy and Physiology | |
| AP | Accounts Payable | |
| AP | Action Potential | |
| AP | Arabian Peninsula | |
| AP | All Purpose (RealTree camoflauge) | |
| AP | Application Process | |
| AP | Automotive Parts | |
| AP | Attack Power | |
| AP | Apostle | |
| AP | Associate Professor | |
| AP | Assistant Professor | |
| Ap | Ampicillin | |
| AP | Applied Physics | |
| AP | Action Plan | |
| AP | Adobe Photoshop | |
| AP | Asset Protection (retail) | |
| AP | Application Program | |
| A/P | Accounts Payable | |
| AP | Academic Press | |
| A/P | Associate Professor | |
| A/P | Advanced Placement (education) | |
| AP | Attachment Parenting (parenting style) | |
| AP | Accelerator Pedal (automotive technology) | |
| AP | Amapa (Brazil) | |
| AP | Another Place (gaming forum) | |
| AP | Anteroposterior | |
| AP | American Pie (movie) | |
| AP | Armor-Piercing | |
| AP | Air Pump | |
| AP | Active Participation (teaching style; also policy framework) | |
| AP | Assistant to the President (LDS Mission) | |
| AP | Arlington Park (race track; Arlington Heights, IL) | |
| AP | Asphalt | |
| AP | Apple Pie | |
| AP | Austin Powers | |
| AP | Almost Perfect | |
| AP | Animal Planet (television network) | |
| AP | American Psycho (movie) | |
| AP | Acupuncture | |
| AP | Amount of Precipitation | |
| AP | Angina Pectoris | |
| AP | Average Power (US DoD) | |
| AP | Amateur Photographer (UK Magazine) | |
| AP | Antennas and Propagation (IEEE) | |
| AP | Alpha Phi (El Camino College Chapter of Alpha Gamma Sigma Honor Society) | |
| AP | Absolute Power (movie) | |
| AP | Application Protocol | |
| AP | Alternative Press (magazine) | |
| AP | Administrative Procedure | |
| AP | Atmospheric Pressure | |
| AP | Associate Producer (various organizations) | |
| AP | All Points | |
| AP | Applique | |
| AP | Alan Parsons (musician) | |
| AP | Action Point | |
| AP | Adjunct Professor | |
| AP | Autopilot | |
| AP | American Plan | |
| A/P | Action Point | |
| AP | Annual Plan | |
| AP | Animal Protein | |
| AP | Amapá (Brazilian state) | |
| AP | Anatomic Pathology | |
| AP | Adrian Peterson (football player) | |
| AP | Anchor Point (US DoD) | |
| AP | Audience Participation | |
| AP | Arbeiderpartiet | |
| A/P | Artist's Proof (also seen as AP) | |
| AP | Access Provider | |
| AP | Ability Power (League of Legends) | |
| AP | Array Processor | |
| AP | Ante Partum (Latin: Before Birth) | |
| A/P | Anterior/Posterior | |
| AP | Alfa Parf (hair care) | |
| A/P | Anatomy and Physiology | |
| AP | Analytical Psychology (Carl Jung) | |
| AP | Artist's Proof (also seen as A/P) | |
| AP | Application Processor | |
| AP | Acute Pain | |
| AP | Antipersonnel | |
| AP | Alianza Popular (Spanish political party) | |
| AP | Anti-Proton (TV show Andromeda) | |
| AP | Ammonium Perchlorate | |
| AP | Advanced Program | |
| AP | After Peak | |
| AP | Analysis Paralysis (gaming) | |
| AP | Aperture Priority (camera) | |
| A/P | Artist's Print | |
| AP | Acid Phosphatase | |
| AP | Accounting Period (USPS) | |
| AP | Air Police | |
| AP | Anterior Posterior (radiology) | |
| AP | Advance Payment | |
| AP | Apparent Power | |
| AP | Aerial Platform | |
| AP | Anisotropy Parameter | |
| AP | Air Publication | |
| AP | Atelier Protégé (French: Sheltered Workshop) | |
| AP | Apurinic | |
| A/P | Active/Passive | |
| AP | Apyrimidinic | |
| AP | Airport Plaza (Crystal City, Arlington, VA) | |
| AP | Academic Psychiatry (journal) | |
| AP | Apothecaries' (possessive) | |
| AP | Acquisition Plan | |
| AP | Application Profile (OSI) | |
| AP | Additional Premium | |
| AP | Associate Program (US Army) | |
| AP | Advanced Purchase | |
| AP | Access Panel | |
| AP | America's Promise (Alliance for Youth) | |
| AP | Attitude Problem | |
| AP | Avrupa Parlamentosu (Turkish: European Parliament) | |
| AP | Authorized Person | |
| aP | Acellular Pertussis | |
| AP | Associate Partner | |
| AP | Administration Pénitentiaire (French: Prison Administration) | |
| AP | Advancement Project | |
| AP | Astral Projection | |
| AP | Antarctic Press (comic book publisher) | |
| AP | Assistance Payments | |
| AP | Answer Print | |
| AP | Agrarian Party | |
| AP | Auxiliary Police | |
| AP | Anthropod | |
| AP | Aged Parent | |
| AP | Advantage Player (gambling) | |
| AP | Arithmetic Progression | |
| AP | Assistant Producer | |
| AP | Anomalous Propagation | |
| AP | Autism Partnership | |
| AP | Auxlliary Propulsion | |
| AP | Athletes' Performance (est. 1999) | |
| AP | Affirmative Procurement | |
| AP | Audio Patchbay (cable) | |
| AP | Academic Pressure | |
| AP | Asian Pride | |
| AP | Advanced Procurement | |
| AP | Annualized Premium | |
| AP | Ability Points (roleplaying games) | |
| AP | Aggregation Point | |
| AP | Acción Popular (Popular Action, Peru) | |
| AP | Alki Point (Washington) | |
| A/P | Automatic Pilot | |
| AP | Advance Party | |
| AP | Ascoli Piceno, Marche (Italian province) | |
| AP | Atypical Pneumonia | |
| AP | anonymous platform (computing) | |
| AP | Applications Process(es) | |
| AP | Allied Perils (insurance) | |
| AP | Academic Proficiency | |
| A/P | Assessment & Plan (medical) | |
| AP | Acupuncture Physician | |
| AP | Apelação (Appeal; Brazil) | |
| AP | As Purchased (ingredients weight for baking or cooking) | |
| AP | Assigned Personnel | |
| AP | Acidification Potential (environmental science) | |
| AP | Astropulse (computing) | |
| AP | Acetone Peroxide (explosive) | |
| AP | Authentication Proxy | |
| AP | Attack Points (gaming) | |
| AP | Appeal Panel | |
| AP | Allied Publication | |
| AP | Alarm Processor (AT&T) | |
| AP | Access Proxy | |
| AP | Alternative Pipe | |
| AP | Armor Penetrating | |
| AP | Approved Permit | |
| AP | Applications Programmer (Tandem) | |
| AP | Accessory Pathway | |
| AP | Adjective Phrase | |
| AP | American Petroleum, Inc. (Ohio) | |
| AP | Accredited Person | |
| AP | Adjunct Processor | |
| AP | Accounting Point | |
| AP | Approving Official | |
| AP | Advanced Prediction | |
| AP | Advance Procurement | |
| AP | Assumed Position | |
| AP | Adaptation Period | |
| AP | Activation Product | |
| AP | Access Permit | |
| AP | Affleck's Palace | |
| AP | Automation Production | |
| AP | Appropriate Projects (Water Charity) | |