In this paper, a single-stage W-band low noise amplifier (LNA) monolithic millimeter-wave integrated circuit (MMIC) has been designed and fabricated using our own InP-based high electron mobility transistor technology. The LNA MMIC is developed in Cascode topology and coplanar waveguide technology, which result in a very compact chip with size of 900 μm × 975 μm and a rather high linear gain over 10 dB from 84 GHz to 100 GHz with the maximum value of 15.2 dB at 95 GHz. To our knowledge, this single-stage LNA MMIC exhibits the highest gain-per-stage and competitive gain-area ratio among reported W-band LNA MMICs. Additionally, the amplifier also demonstrates a relatively low noise figure of 4.3 dB at 87.5 GHz and a fairly high saturated output power of 8.03 dBm at 88.8 GHz at room temperature. The successful fabrication of LNA MMIC is of great significance on building a W-band signal receiver-front-end system.