PET may refer to:

• Parent Effectiveness Training (P.E.T.), a parent education program developed by Thomas Gordon
• Preliminary English Test, an international examination of English proficiency
• Psychometric Entrance Test, an Israeli standardized university entrance exam

A pet or companion animal is an animal kept primarily for a person's company or protection, as opposed to working animals, sport animals, livestock, and laboratory animals, which are kept primarily for performance, agricultural value, or research. The most popular pets are noted for their attractive appearances and their loyal or playful personalities.