Ion Cyclotron Resonance Heating (ICRH) experiment have been carried out in a wide range of JET Plasmas. A high confinement region in the plasma core has been discovered during on-axis heating of pellet fueled discharges. Sawttoth-free periods and improved heating efficiency have been achieved in high current plasmas by heating during the current rise. Combined ICRH and neutral beam injection (NBI) in double null X-point plasmas has yields D-D fusion rates up to 2x1016 s-1 and electron and ion temperatures of 11keV and 17keV respectively. Non-thermal fusion reaction rates from (He3) D minority ICRH have been reproduced by a model which predicts Q~0.7 for (D)T minority ICRH in JET. RF modulation studies have yielded power deposition profiles and heat transport coefficients inside the q=1 surface. Alignment of the antenna screen to the magnetic field minimises nickel impurity release.