Abstract Diamond, as an ultra-wide bandgap semiconductor, has become a promising candidate for next-generation microelectronics and optoelectronics due to its numerous advantages over conventional semiconductors, including ultrahigh carrier mobility and thermal conductivity, low thermal expansion coefficient, and ultra-high breakdown voltage, etc. Despite these extraordinary properties, diamond also faces various challenges before being practically used in the semiconductor industry. This review begins with a brief summary of previous efforts to model and construct diamond-based high-voltage switching diodes, high-power/high-frequency field-effect transistors, MEMS/NEMS, and devices operating at high temperatures. Following that, we will discuss recent developments to address scalable diamond device applications, emphasizing the synthesis of large-area, high-quality CVD diamond films and difficulties in diamond doping. Lastly, we show potential solutions to modulate diamond’s electronic properties by the “elastic strain engineering” strategy, which sheds light on the future development of diamond-based electronics, photonics and quantum systems.