  The lattice thermal conductivity ($\kappa_{\rm L}$) of PbTiO$_3$ (PTO) is
estimated using a combination of {\em ab initio} calculations and semiclassical
Boltzmann transport equation. The computed $\kappa_{\rm L}$ is remarkably low,
nearly comparable with the $\kappa_{\rm L}$ of good thermoelectric materials
such as PbTe. In addition, a semiclassical analysis of the electronic transport
quantities is presented, which suggests excellent thermoelectric properties,
with a figure of merit $zT$ well over 1 for a wide range of temperature. For
thermoelectric applications, the $\kappa_{\rm L}$ could be further reduced by
utilizing different morphologies and compositions.
