  We investigate particle motion in the vicinity of a $4D$
Einstein-Gauss-Bonnet (EGB) black hole immersed in external asymptotically
uniform magnetic field. It is well known that magnetic fields can strongly
affect charged particle motion in the black hole vicinity due to the Lorenz
force. We find that the presence of the Gauss-Bonnet (GB) coupling gives rise
to a similar effect, reducing the radius of the innermost stable circular orbit
(ISCO) with respect to the purely relativistic Schwarzschild black hole.
Further, we consider particle collisions in the black hole vicinity to
determine the center of mass energy and show that this energy increases with
respect to the Schwarzschild case due to the effect of the GB term. Finally, we
consider epicyclic motion and its frequencies and resonance as a mean to test
the predictions of the model against astrophysical observations. In particular
we test which values of the parameters of the theory best fit the 3:2 resonance
of high-frequency quasi-periodic oscillations in three low-mass X-ray binaries.
