Thermochronology can reconstruct the thermal history of a rock based on thermally resetting radiometric age, which is useful for estimating a regional exhumation history when applied to rocks exhumed from a great depth. In particular, systems having lower closure temperatures are called “low-temperature thermochronology” and have been used to study tectonics in the shallow crust. In this paper, low-temperature thermochronology and its application to tectonics in the shallow crust are comprehensively reviewed, focusing particularly on the uplift and exhumation histories of mountainous regions. This review paper comprises two parts. In the first part, fundamentals of low-temperature thermochronology are reviewed, including some representative thermochronometers, mathematical descriptions of thermal annealing/diffusion, concepts of closure temperature and partial annealing/retention zone, and inversion method for computing thermal history on the basis of thermochronologic data. In the second part, application to mountain formation is described, including terminology of uplift and exhumation, methodology for estimating cooling and exhumation history based on cooling ages, and some representative case studies around the world.