  Using Floquet theory, we illustrate that Floquet Weyl fermions can be created
in circularly-polarised-light-irradiated three-dimensional stacked graphene
systems. One or two semi-Dirac points can be formed due to overlapping of
Floquet sub-bands. Each pair of Weyl points have a two-component semi-Dirac
point parent, instead of a four-component Dirac point parent. Decreasing the
light frequency will make the Weyl points move in the momentum space, and the
Weyl points can approach to the Dirac points when the frequency becomes very
small. The frequency-amplitude phase diagram is worked out. It is shown that
there exist Fermi arcs in the surface Brillouin zones in
circularly-polarised-light-irradiated semi-infinitely-stacked and
finitely-multilayered graphene systems. The Floquet Weyl points emerging due to
the overlap of Floquet sub-bands provide a new platform to study Weyl fermions.
