A TiS\(_{2}\) crystal with a layered structure was found to have a large thermoelectric power factor.The in-plane power factor \(S^{2}/ \rho\) at 300 K is 37.1~\(\mu\)W/K\(^{2}\)cm with resistivity (\(\rho\)) of 1.7 m\(\Omega\)cm and thermopower (\(S\)) of -251~\(\mu\)V/K, and this value is comparable to that of the best thermoelectric material, Bi\(_{2}\)Te\(_{3}\) alloy. The electrical resistivity shows both metallic and highly anisotropic behaviors, suggesting that the electronic structure of this TiS\(_{2}\) crystal has a quasi-two-dimensional nature. The large thermoelectric response can be ascribed to the large density of state just above the Fermi energy and inter-valley scattering. In spite of the large power factor, the figure of merit, \(ZT\) of TiS\(_{2}\) is 0.16 at 300 K, because of relatively large thermal conductivity, 68~mW/Kcm. However, most of this value comes from reducible lattice contribution. Thus, \(ZT\) can be improved by reducing lattice thermal conductivity, e.g., by introducing a rattling unit into the inter-layer sites.