In this study, the electromagnetic (EM) performance of talc/NiTiO3 composite was evaluated. The morphology of talc displayed a lamella structure; there were many nanoparticles of NiTiO3 coated on the talc lamella. Thermal destruction occurred, which increased the surface area from 2.51 m2 g−1 to 79.09 m2 g−1 at the calcined stage at 650°C. The presence of NiTiO3 increased dielectric loss and magnetic loss of talc. The calculation of EM wave absorption of talc/NiTiO3 obtained a maximum reflection loss of −11.94 dB at the thickness of 6.85 mm; the optimum thickness for microwave absorption is 6.3–7.3 mm. This study revealed a new approach for fabricating an EM absorber and broadening applications of both talc and NiTiO3 in EM absorption.