  We report a strategy to induce superconductivity in the BiS$_2$-based
compound LaOBiS$_2$. Instead of substituting F for O, we increase the
charge-carrier density (electron dope) via substitution of tetravalent
Th$^{+4}$, Hf$^{+4}$, Zr$^{+4}$, and Ti$^{+4}$ for trivalent La$^{+3}$. It is
found that both the LaOBiS$_2$ and ThOBiS$_2$ parent compounds are bad metals
and that superconductivity is induced by electron doping with \emph{T$_c$}
values of up to 2.85 K. The superconducting and normal states were
characterized by electrical resistivity, magnetic susceptibility, and heat
capacity measurements. We also demonstrate that reducing the charge-carrier
density (hole doping) via substitution of divalent Sr$^{+2}$ for La$^{+3}$ does
not induce superconductivity.
