A fluid supply system includes: a coupling manifold disposed in parallel to mutually facing end portions of the multiple-unit manifolds that are adjacent to each other; a first fluid control device connecting one of the end portions of the multiple-unit manifolds that are adjacent to each other to the coupling manifold; and a second fluid control device connecting the other one of the end portions of the multiple-unit manifolds that are adjacent to each other to the coupling manifold, in which the coupling manifold has a communication passage that establishes communication of combined flow passages of the multiple-unit manifolds that are adjacent to each other via the first and second fluid control devices.