OER

OER or Oer may refer to:


 * Odakyu Electric Railway, a Japanese railway company
 * Oer family, a German noble family
 * Oer-Erkenschwick, a town in North Rhine-Westphalia, Germany
 * Offense efficiency rating, the average number of points scored per shot by a basketball player
 * Officer Evaluation Report, an evaluation form used by the United States Army
 * Open educational resources, open documents that are useful for teaching, learning, educational, assessment and research purposes
 * Oregon Electric Railway, an interurban railroad line in Oregon, United States
 * Örnsköldsvik Airport in Örnsköldsvik, Sweden
 * Oxygen enhancement ratio, effect magnitude of ionizing radiation due to the presence of oxygen
 * Oxygen Evolution Reaction, the formation of oxygen by electrochemical reduction of water
 * Owner’s Equivalent Rent, an economic metric for housing prices often used in the calculation of market baskets