This paper reviews research on paleotsunami deposits in the Tohoku region, which began with investigations of lacustrine deposits along the coastal area of the Japan Sea in the 1980s. Subsequently, deposits of the 1611 Keicho, 1454 Kyotoku, and 869 Jogan tsunamis were identified. There is abundant historical and geological evidence of the 1611 tsunami, although its source is still unclear, with possibilities including offshore of Sanriku coast or the southern Kuril Trench. The other two historical tsunamis (1454 and 869) are modeled as having an offshore Sendai source, with a moment magnitude (M_w) of greater than 8.4–8.6. In addition, tsunami deposits older than the 869 Jogan event have been reported in the Tohoku region, but their sources remain unknown.