The demand for enhancement of computational performance has been primarily driven by the continued scaling of CMOS transistors. However, as gate lengths approach single digits, this method alone is not sustainable in the future, and as such, requires new devices to complement advanced CMOS technology. The goal of this thesis is to evaluate the potential complementary device applications that can be enabled through threshold switching-based materials and devices. This work will highlight the design, fabrication, and engineering strategies using threshold switching phenomena that can not only enhance the performance of conventional logic, but also memory and millimeter wave technology for continued improvements in computational performance. The work will discuss the application of threshold switches to three device architectures – (1) a hybrid transistor design, Phase-FET, where the innate abrupt switching nature and orders of magnitude change in resistivity are used to surpass conventional transistor performance (2) cross-point selectors, where the large ON-OFF resistivity ratio can aid in the suppression of sneak-path leakage current for high density memory arrays and (3) a mm-wave RF switch, where the abrupt switching phenomenon in the threshold switch can be triggered using mm-wave pulses to enable RF circuits over wide temperature ranges.