Transistors utilizing carbon nanotube (CNT) thin films have exhibited high on-currents and mobilites greater than those of alternative channel materials. One critical problem that has limited the utilization of CNT thin-film transistors (TFTs) is the occurrence of unavoidable parasitic current paths stemming from metallic nanotubes. In this work, we experimentally demonstrate high-yield, high-performance TFTs composed of a highly purified single-walled carbon nanotube (SWNT) network. A solution process for a highly separated 99.9% semiconducting SWNT solution is used to acquire a significant enhancement in transistor performance, such as a high on/off ratio, high mobility, and high yields close to 100%.