A tire mount position detection system that detects each tire (31 to 36) having a transmitter (41 to 46) is mounted to which wheel position in a vehicle, the tire mount position detection system comprising: a receiver unit arranged in the vehicle to receive a radio signal transmitted by the transmitter (41 to 46), the receiver unit comprising at least a first receiver, and a second receiver arranged at a position different from a position of the first receiver; a first measurement portion that measures first signal intensity, which is intensity of the radio signal received by the first receiver, for each transmitter (41 to 46); a second measurement portion that measures second signal intensity, which is intensity of the radio signal received by the second receiver, for each transmitter (41 to 46); a calculation portion that calculates a total value of the first signal intensity and the second signal intensity, for each transmitter (41 to 46); and a position detection portion that detects the wheel position to which the tire (31 to 36) having the transmitter (41 to 46) is mounted, based on the first signal intensity, the second signal intensity, and the total value of each transmitter (41 to 46), wherein: the calculation portion calculates the total value of the first signal intensity and the second signal intensity, and an intensity ratio, which is a ratio using the first signal intensity and the second signal intensity, for each transmitter (41 to 46); and the position detection portion detects the wheel position to which the tire having the transmitter (41 to 46) is mounted, based on the first signal intensity, the second signal intensity, the total value, and the intensity ratio of each transmitter (41 to 46). a receiver unit arranged in the vehicle to receive a radio signal transmitted by the transmitter (41 to 46), the receiver unit comprising at least a first receiver, and a second receiver arranged at a position different from a position of the first receiver; a first measurement portion that measures first signal intensity, which is intensity of the radio signal received by the first receiver, for each transmitter (41 to 46); a second measurement portion that measures second signal intensity, which is intensity of the radio signal received by the second receiver, for each transmitter (41 to 46); a calculation portion that calculates a total value of the first signal intensity and the second signal intensity, for each transmitter (41 to 46); and a position detection portion that detects the wheel position to which the tire (31 to 36) having the transmitter (41 to 46) is mounted, based on the first signal intensity, the second signal intensity, and the total value of each transmitter (41 to 46), wherein: the calculation portion calculates the total value of the first signal intensity and the second signal intensity, and an intensity ratio, which is a ratio using the first signal intensity and the second signal intensity, for each transmitter (41 to 46); and the position detection portion detects the wheel position to which the tire having the transmitter (41 to 46) is mounted, based on the first signal intensity, the second signal intensity, the total value, and the intensity ratio of each transmitter (41 to 46). the calculation portion calculates the total value of the first signal intensity and the second signal intensity, and an intensity ratio, which is a ratio using the first signal intensity and the second signal intensity, for each transmitter (41 to 46); and the position detection portion detects the wheel position to which the tire having the transmitter (41 to 46) is mounted, based on the first signal intensity, the second signal intensity, the total value, and the intensity ratio of each transmitter (41 to 46).