  We develop a classical two-dimensional bi-scalar gravity based on the
Kaluza-Klein reduction applied to the four-dimensional Horndeski theory. One of
the scalar fields arises from the original four-dimensional theory, while the
extra scalar emerges from the reduction process. We also introduce a
two-dimensional bi-scalar identity that allows for a more concise and elegant
reformulation of the resulting bi-scalar Lagrangian. Additionally, we study the
linear perturbations around a static background to demonstrate that the
bi-scalar theory may support a single healthy propagating mode. Furthermore, by
restricting the scalar fields, we investigate a general single scalar theory
that is identical to the two-dimensional Horndeski theory up to a boundary
term. Our results provide a framework to map a generic two-dimensional dilaton
gravity into four-dimensional Horndeski theory.
