Roughly 60 blazars have been identified with >100 MeV EGRET γ-ray sources, and show inferred isotropic luminosities as large as 3×1049 ergs s−1. The two most remarkable characteristics about the EGRET observations are that the γ-ray luminosity often dominates the bolometric power, and that variability on time-scales of one day or less is seen from several sources. Gamma-ray blazars have been detected with redshifts ranging from ≅0.03 to ≅2.3. The distribution of redshifts is similar to that of flat spectrum radio quasars. The distribution of >100 MeV photon spectral indices for strong detections is well described by a Gaussian function peaking near 2.16 with a standard deviation of 0.31. In some cases, flare spectra at >100 MeV energies are harder than spectra in quiescence. Blazar spectra at hard X-ray and soft γ-ray energies have harder spectra and, from analyses of contemporaneous data sets, the change in spectral index clearly exceeds 0.5 for 3C 273 and marginally exceeds 0.5 for PKS 0528+134. An inde...