A scalar-tensor theory of gravitation is constructed using a non-Riemannian geometry in which both the metric tensor and the scalar function have an unambiguous geometric interpretation. The scalar function is introduced by defining a linear connection with nonvanishing torsion. The field equations of the theory, and the Lagrangian from which they are derived, are identical to those given by Dicke in an alternate formulation of the Brans-Dicke theory. By using the static spherically symmetric solution to the field equations it is found that, with a proper choice of parameter, this theory agrees with experimental results in the three classical tests of a gravitational theory.