A temperature measurement system includes: a laser light source; an optical fiber; and a temperature measurement unit configured to acquire a measured temperature distribution of a temperature of a temperature measurement area along an installation path of the optical fiber by detecting backscattered light of the incident laser light in the optical fiber, wherein the temperature measurement unit sequentially makes a correction for the measured temperature distribution a plurality of times so as to make a square error between a convolution of a transfer function of the optical fiber along the installation path and the corrected temperature distribution and the measured temperature distribution smaller in each of the corrections, and the temperature measurement unit also replaces a corrected temperature at a specific point of the installation path with an estimated temperature at the specific point in each of the corrections.