5G, with its ultra-low latency and high data throughput, is paving the way for a fully digitalized and connected world. However, the fact that 5G uses high frequencies brings the challenge of short signal propagation. Consequently, deploying many small cells to create an ultra-dense network becomes essential. IDTechEx has been studying 5G-related topics for many years and this report "5G small cells 2021-2031: Technologies, Markets, Forecasts" is built on our expertise, covering the main technologies, players, and markets for the 5G small cell industry. Moreover, IDTechEx also provides a series of detailed case studies on selected high potential verticals where 5G small cells can be applied to.