The present disclosure relates to a gas distribution apparatus for substrate processing apparatuses, including: a distribution body distributing a process gas toward a substrate supporting unit supporting a substrate; a first injection hole provided in the distribution body, a process gas which is to be distributed toward the substrate supporting unit being injected through the first inject hole; and a second injection hole provided in the distribution body at a position spaced apart from the first injection hole, a process gas which is to be distributed toward the substrate supporting unit being injected through the second inject hole, and a substrate processing apparatus.