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)