The absorption coefficient, reflectivity, and electroreflectance of SrTiO3 in the neighborhood of the fundamental absorption edge are reported. The absorption coefficient shows an exponential rise with incident energy (Urbach rule) over five orders of magnitude. Its logarithm has a slope of 1kT. The data indicate that the band gap of SrTiO3 is about 3.4 eV. Additional results for reduced SrTiO3 show that Redfield's model for an exponential edge is not applicable to this material. The reflectivity indicates structure in the region of 3.4 eV and the electroreflectance shows an appreciable signal from 2.5 to 5.0 eV with some structure near 3.4 eV. The electroreflectance signal appears to be due to some process other than the Franz-Keldysh effect. It could be due to a shift or splitting in the major oscillator (4.4 eV) responsible for the refractive index, with induced lattice polarization.