Provided are an overhead hoist transfer system and a factory system employing the same. The factory system includes a rail attached to a ceiling of a factory. An overhead hoist transfer system, in which a first carrier configured to receive a first material and a second carrier configured to receive a second material may be suspended and moved along the rail, is provided. A processing device system including a first carrier port in which the first carrier may be seated, a first device gate through which the first material may pass, a second carrier port in which the second carrier may be seated, and a second device gate through which the second material may pass, is provided. The processing device system may be adjacent to the rail. The overhead hoist transfer system includes a grip unit configured to grip the first carrier or the second carrier, and a rotating unit configured to rotate the grip unit.