This brief presents an overview of the recent progress on silicon-based millimeter-wave SoCs for short-range radar in imaging and sensing applications. The process, operating frequency, and basic architectures for short-range millimeter-wave radar are firstly summarized. Then, topology and performance of excellent radar SoCs are reviewed from different applications: automotive radar, gesture recognition, vital signs monitoring, security and biomedical sensing, industrial detection and imaging. Future trends in millimeter-wave SoCs for short-range radar are also discussed.