This paper presents a millimeter wave power amplifier (PA) implemented in 22nm FD-SOI technology with only 0.8V transistors. The single stage pseudo-differential 3-level stacked PA operating between 55GHz and 62GHz is optimized for output power and area consumption. The input and output matching networks utilize transformer baluns to minimize loss and size. An output power of 15dBm and a power added efficiency (PAE) of 11.8 % at 55GHz are measured. The PA is fabricated in an area of only 0.055mm² without pads. Compared against the state of the art millimeter-wave PAs in CMOS technologies, the presented design has the lowest supply voltage per transistor and still the second highest output power over area value.