This letter presents novel high power and reliable radio frequency (RF) microelectromechanical systems switches with single-pole single-throw (SPST) and single-pole triple-throw (SP3T) configurations. An in-plane movable structure with a single layer is made using a simple standard silicon-on-insulator process, which greatly reduces the micro-fabrication complexity and cost compared with the previously reported multi-contact switches with out-of-plane movable structures. The SPST switch achieves a uniform current distribution through each contact, thereby increasing the power handling capability of the switch. The SP3T switch is a derivative of the SPST switch with separate individual actuations. The experimental results demonstrate that the fabricated switches have superior RF performances: insertion losses are -0.9 and -1.3 dB at 6 GHz for SPST and SP3T switches, respectively, whereas isolations are better than -29 and -37 dB from dc to 6 GHz for SPST and SP3T switches, respectively. In hot-switching conditions, the SPST switch can handle RF power up to 2 W for 10 million cycles, whereas the SP3T switch is capable of handling an RF power of 1 W for 7 million cycles before failure occurs.