  The structure of an interior dipole magnetic field of neutron stars in $f(R)$
gravity is considered. For this purpose, the perturbative approaches are used
when both the deviations from general relativity and the deformations of
spherically symmetric configurations associated with the presence of the
magnetic field are assumed to be small. Solutions are constructed which
describe relativistic, spherically symmetric configurations consisting of a
gravitating magnetized perfect fluid modeled by a realistic equation of state.
Comparing configurations from general relativity and modified gravity, we
reveal possible differences in the structure of the magnetic field which occur
in considering neutron stars in modified gravity.
