The electronic Fabry-Pérot interferometer operating in the quantum Hall regime may be a promising tool for probing edge state interferences and studying the non-Abelian statistics of fractionally charged quasiparticles.Here we report on realizing a quantum Hall Fabry-Pérot interferometer based on monolayer graphene.We observe resistance oscillations as a function of perpendicular magnetic field and gate voltage both on the electron and hole sides.Their Coulomb-dominated origin is revealed by the positive (negative) slope of the constant phase lines in the plane of magnetic field and gate voltage on the electron (hole) side.Our work demonstrates that the graphene interferometer is feasible and paves the way for the studies of edge state interferences since high-Landau-level and even denominator fractional quantum Hall states have been found in graphene.