  The three dimensional black hole solutions of Ba\~nados, Teitelboim and
Zanelli (BTZ) are dimensionally reduced in various different ways. Solutions
are obtained to the Jackiw-Teitelboim theory of two dimensional gravity for
spinless BTZ black holes, and to a simple extension with a non-zero dilaton
potential for black holes of fixed spin. Similar reductions are given for
charged black holes. The resulting two dimensional solutions are themselves
black holes, and are appropriate for investigating exact ``S-wave'' scattering
in the BTZ metrics. Using a different dimensional reduction to the string
inspired model of two dimensional gravity, the BTZ solutions are related to the
familiar two dimensional black hole and the linear dilaton vacuum.
