  Plasmonic nanoantennas is a hot and rapidly expanding research field. Here we
overview basic operating principles and applications of novel magneto-plasmonic
nanoantennas, which are made of ferromagnetic metals and driven not only by
light, but also by external magnetic fields. We demonstrate that
magneto-plasmonic nanoantennas enhance the magneto-optical effects, which
introduces additional degrees of freedom in the control of light at the
nano-scale. This property is used in conceptually new devices such as
magneto-plasmonic rulers, ultra-sensitive biosensors, one-way subwavelength
waveguides and extraordinary optical transmission structures, as well as in
novel biomedical imaging modalities. We also point out that in certain cases
'non-optical' ferromagnetic nanostructures may operate as magneto-plasmonic
nanoantennas. This undesigned extra functionality capitalises on established
optical characterisation techniques of magnetic nanomaterials and it may be
useful for the integration of nanophotonics and nanomagnetism on a single chip.
