Motivated by the recent LHC discovery of the di-photon excess at the invariant mass of ~ 750 GeV, we study the prospect of investigating the scalar resonance at a future photon-photon collider. We show that, if the di-photon excess observed at the LHC is due to a new scalar boson coupled to the standard-model gauge bosons, such a scalar boson can be observed and studied at the photon-photon collider with the center-of-mass energy of ~ 1 TeV in large fraction of parameter space.