An analytical study to investigate the local buckling capacity of steel I-section beams under elevated temperatures is presented. The study is based on an inelastic local buckling stability model that was developed by the author. The study is focused on I-section beams loaded in pure bending and subjected to either uniform or linear temperature gradient through the section depth. A parametric study is presented to investigate the effect of section geometry, steel type, and temperature gradient on local buckling capacity. The parametric study results are used to propose a new method to estimate the local buckling capacity of I-section beams under elevated temperatures. A numerical example is presented to illustrate the use of the proposed method.