Bismuth iron oxide, BiFeO3, has emerged as a leading multiferroic material with combined ferroelectric and ferromagnetic features relevant to high frequency communications and information processing. Recent advances in thin film growth of these materials have led to dramatic improvements in magnetic polarization. The growth-dependent localized electronic states within these ultrathin films, at their domain walls, at their free surfaces, and at their metal interfaces can degrade ferroelectric, magnetic, electronic, and optical properties. Yet these properties have until now remained unexplored. Of particular interest are the .bulk. trap states due to native and morphological defects that can degrade frequency response and dielectric loss, but also the tradeoff between thickness-dependent phase formation and the .dead layers. at the outer few nanometers of these films. We have used depth-resolved cathodoluminescence spectroscopy (DRCLS) combined with X-ray diffraction, atomic force microscopy, and susceptibility measurements to measure and compare the band and defect properties of BiFeO3 (BFO) films grown by off-axis plasma sputtering. DRCLS of high quality, sputtered BFO films tens to hundreds of nanometers thick on SrTiO3 (STO) substrates reveal features due to defects and near-surface phase changes. These results indicate that defect properties of multiferroic thin films can now be assessed and correlated with electronic and structural properties vs. growth conditions.