This study investigates the upper-limit ages of the Tsurugidake Landslides, which resulted from the collapse of a lava dome on the northern foot of Kurikoma Volcano, Tohoku Region, Japan. Age constraints were determined using tephrochronology and radiocarbon （¹⁴C） date of wetland and aeolian deposits covering the landslide masses. The results indicate that the Tsurugidake Landslides A, B, and C were formed before 5.3, 3.5 and 1.0 cal ka （corresponding to AD915; Age of To-a tephra）, respectively. The Tsurugidake Lava Dome, formed by the latest magma eruption of Kurikoma Volcano in 8.1 – 6.4 cal ka, collapsed within ～2,800 years after its emplacement.