A vital information measurement device and a vehicle seat which improves the durability of sheet-shaped sensors configured to detect vital information of a seated passenger and which can stably measure the heart rate of the seated passenger. A vehicle seat S includes sheet-shaped sensors 20 attached to a seat back 2, and can measure the heart rate of a seated passenger based on vital signals of the seated passenger detected by the sheet-shaped sensors 20. At each sheet-shaped sensor 20, a sensor overlap reduction section is provided to reduce partial overlapping of the sheet-shaped sensor 20 when the seated passenger leans on the seat back 2. Specifically, each sheet-shaped sensor 20 includes a first cutout extending toward the center of the sheet-shaped sensor 20 at an outer peripheral portion of the sheet-shaped sensor 20, and a second cutout formed continuously from the first cutout and extending opposite to the center along the outer peripheral portion of the sheet-shaped sensor 20.
