  The electrogravity transformation is defined by an interchange of the
``active'' and ``passive'' electric parts of the Riemann tensor. Such a
transformation has been used to find new solutions that are ``dual'' to the
Kerr family of black hole spacetimes in general relativity. In such a case, the
dual solution is a similar black hole spacetime endowed with a global monopole
charge. Here, we extend this formalism to obtain solutions dual to the static,
spherically symmetric solutions of two different scalar-tensor gravity
theories. In particular, we first study the duals of the charged black hole
solutions of a four-dimensional low-energy effective action of heterotic string
theory. Next, we study dual of the Xanthopoulos-Zannias solution in Brans-Dicke
theory, which contains a naked singularity. We show that, analogous to general
relativity, in these scalar-tensor gravity theories the dual solutions are
similar to the original spacetimes, but with a global monopole charge.
