The millimeter-wave spectrum has sparked interest recently as a promising alternative to meet bandwidth requirements for wireless local area networks, vehicular radars, short-range multi-Gb/s links, and next-generation cellular system communications (5G). The unlicensed 7 GHz ISM band around 60 GHz is of particular interest. Compared to semiconductor technologies, Micro-Electro-Mechanical Systems (MEMS) have the potential to realize reconfigurable millimeter-wave devices with superior performance in terms of linearity, insertion loss and DC power consumption.This thesis presents the development and fabrication of miniaturized, low insertion loss, high isolation RF-MEMS switches implemented in CMOS chips through the use of a post-processing technique. Several CMOS-MEMS switches operating at 60 GHz and 77 GHz are demonstrated. Prototype units for SPST, SP3T switches and a distributed MEMS transmission line (DMTL) network are integrated on CMOS 0.35 μm. The challenges involved in realizing CMOS-MEMS devices at mm-wave frequencies are also addressed in this work.