We obtained the analytical expression for the effective thermoelectric properties and dimensionless figure of merit of a composite with interfacial electrical and thermal resistances using a micromechanics-based homogenisation. For the first time, we derived the Eshelby tensor for a spherical inclusion as a function of the interfacial resistances and obtained the solutions of the effective Seebeck coefficient and the electrical and thermal conductivities of a composite, which were validated against finite-element analysis (FEA). Our analytical predictions well match the effective properties obtained from FEA with an inclusion volume fraction up to 15%. Because the effective properties were derived with the assumption of a small temperature difference, we discuss a heuristic method for obtaining the effective properties in the case where a thermoelectric composite is subjected to a large temperature difference. (C) 2019 Elsevier Ltd. All rights reserved.