We provide a method to determine the motion of a classical massive particle in a background geometry of two-dimensional gravity theories, for which the Birkhoff theorem holds., In particular, we get the particle trajectory in a continuous class of two-dimensional dilaton gravity theories that includes the Callan-Giddings-Harvey-Strominger model, the Jackiw-Teitelboim model, and the d-dimensional s-wave Einstein gravity. The explicit trajectory expressions for these theories are given along with the discussions on the results.