Photons produced during collisions of protons at high energy are components of some of the most interesting physics signatures that can be studied at the LHC. The study of single photon production leads to an understanding of proton structure and the fragmentation of remnants of proton collisions. Photons can also be used to search for undiscovered particles. This talk focuses on two analyses conducted using prompt photons: the measurement of the inclusive prompt photon cross section and the search for a Higgs boson decaying to two photons on ATLAS.