Localized magnetism exists on the surface of niobium, as evidenced by experiments and supported by theory. Point contact spectroscopy, SQUID, and EPR measurements show the presence of paramagnetic moments in niobium oxides that increase with mild baking and decrease with high temperature baking. Theoretical modeling of the residual resistance matches experimental data and attributes it to magnetic impurities in the niobium oxide layer, with a concentration of around 250 ppm or 6×1012/cm2. Surface treatments like baking modify the concentration of magnetic moments, providing an explanation for changes in cavity performance.