High‐efficiency and high‐linearity three‐stage transformer‐coupled power amplifier (PA) and power combiner for millimeter‐wave applications using 130 nm CMOS technology are presented in the paper. The suggested PA uses transformer coupled for input, inter‐stage, and output matching networks where the inter‐stage matching inductors are utilized to enhance the RF performance. The proposed power amplifier is composed of three stages: first, driver, and power stages. The first stage operates in a class‐C to improve the efficiency and decrease power dissipated while a class‐AB is used in the driver and power stages to maximize the output power. The proposed PA and power combiner designs are suitable for mm‐wave 5G applications. The coupling transformers, inter‐stage matching inductors, and output combiner are analyzed and designed using Ansoft high‐frequency structure simulator (HFSS)