Nanoantennas : new prospects in light matter interactions The possibilities of nanoantennas for an enhanced interaction of light with quantum systems is theoretically investigated. A versatile framework is introduced to describe this interaction. A classical electrodynamics description of nanoantennas enables to freely design and tune them for specific means. But this approach leads to a semiclassical description of the entire system. We introduce a quantization scheme for nanoantennas based on their quasinormal modes which enables a fully quantum treatment of the hybrid system. We show how nanoantennas can be designed to enhance the rates of so called dipole forbidden transitions of quantum systems since the electromagnetic fields in the vicinity of a nanoantenna may vary much stronger than for plane waves. Specifically an electric quadrupole excitation rate can be enhanced in the gap of a dimer nanoantenna. In regard to the specifics of an assumed quantum system this excitation can cause a luminescence enhancement.We suggest using a hybrid quantum system consisting of a nanoantenna and a quantum system as an ultra bright single photon source. Due to its interaction with a nanoantenna a quantum system can spontaneously emit radiation at higher rates when compared to free space. But this enhancement is not the only important figure of merit for single photon sources. A trade off between emission rate and nonclassicality of the emitted light is found as well. We investigate how quantum systems may be strongly coupled to nanoantennas. Fundamental trade offs may set ultimate limits for achievable coupling to loss ratios. To realize the strong coupling regime nanoantennas have to be sufficiently small which causes comparably low efficiencies. If a strongly coupled hybrid system is pumped its dynamics and spectral response depends considerably on the excitation strength. The effects of strong coupling are most pronounced for weak excitations.