EOR could refer to:Earth orbit rendezvous, a proposed method for space missions to the Moon Electric orbit raising, a method in space technology of reaching higher orbits by means of electric propulsion Electro-optic rectification, a non-linear optical process Employer of record, a co-employment company Engineer of record, a licensed engineer responsible for the design and construction phases of a project Enhanced oil recovery, a term in petroleum production Epping Ongar Railway, a heritage railway in England European ordering rules, a standard to put words or names into sequence Exclusive or, the exclusive disjunction in logic Epoch of Reionization, a process that reionized matter in the universe. Economics of Religion, a field of study using economics to understand religion the IOC country code for the Refugee Olympic Team since the 2020 Olympics the character Eeyore from the Winnie the Pooh series.