A fully differential 60 GHz three-stage transformer-coupled amplifier is designed and implemented in 65 nm digital CMOS process. On-chip transformers which offer DC biasing for individual stages, extra stabilization mechanisms, and simultaneous input/inter-stage/output matching networks are used to facilitate a compact circuit design. With a cascoded circuit configuration, the amplifier is tested with a linear gain of 30.5 dB centered at 63.5 GHz and a 40 dB reverse isolation under a 1 V supply. The amplifier delivers 9 dBm and 13 dBm output power under 1 V and 1.5 V supplies, respectively and occupies a core chip area of 0.05 mm2. The measurement results validate a high gain and area efficient power amplifier design methodology in deep-scaled CMOS for millimeter-wave communication system applications.