A low‐energy diffuse scattering electron spin detector for spin‐resolved x‐ray photoelectron spectroscopy (SRXPS) is described. The detector is coupled to a commercial 152‐mm mean radius, 150° spherical sector electrostatic electron energy analyzer. Electron optics are described for both the transport of photoelectrons from the energy analyzer exit slit to the gold scattering target, and from the gold target to the spin analyzer electron detectors. The spin detector has an effective Sherman function of 0.078±0.008, with a figure of merit of approximately 4×10−5. The electron optical phase space acceptanceEA&OHgr; of the detector is 623 eV mm2 sr. The SRXPS apparatus performance is demonstrated with SRXPS spectra from ferromagnetic Fe and a cobalt‐based ferromagnetic glass.