The present invention relates to an R-T-B-based sintered magnet including: a rare earth element R; a metal element T which is Fe, or includes Fe and Co with which a part of Fe is substituted; boron; and a boride forming element M which is a metal element other than rare earth elements and the metal element T and forms a boride, in which the R-T-B-based sintered magnet includes: a main phase which includes a crystal grain of an R-T-B-based alloy; and a boride phase which includes a compound phase based on the boride of the boride forming element M, and is generated on a preferential growth plane of the crystal grain of the main phase.