PEI or Pei may refer to:
Places Matecaña International Airport, Pereira, Colombia, IATA code PEI Pei County (沛县), Jiangsu, China Pei Commandery (沛郡), a commandery in Chinese history Prince Edward Island, a province of Canada Pei, Tibet, a town in Tibet
People Bei (surname) (貝), romanized Pei in Wade–Giles Pei (surname), a Chinese surname (裴) or an Italian surname I. M. Pei (1917–2019), a Chinese-American architect Mario Pei (1901–1978), an Italian-American linguist
Polymers Polyetherimide (PEI), a thermoplastic similar to PEEK Polyethylenimine (PEI), a type of water-soluble polymer
Other uses Paul Ehrlich Institute, Germany Pei language Pe (Semitic letter) (פ), or pei, a letter in the Hebrew alphabet Princeton Environmental Institute of Princeton University Private Education Institution (Singapore) Shar Pei, a wrinkled dog breed Pie Pee (disambiguation)