The 'Bombing of Toyohashi' by Major General Curtis E. LeMay’s US 20^th Army Air Force as part of the strategic bombing campaign mounted by the USA against the Japanese home islands in the last stages of World War II (20/21 June 1945).

In World War II Toyohashi in the Aichi prefecture was an important hub in the transportation network of central Japan: Toyohashi station was located on the Tokaido main line linking Tokyo and Osaka, and was also the origin of the Iida and Atsumi lines which facilitated access to the rural areas of eastern Aichi prefecture. The city had a fairly small industrial base at the time, but it was more important for its port facilities on Mikawa Bay. In addition to these strategic civilian targets, Toyohashi hosted a number of military targets, such as a large training area, near Aichi university, for Imperial Japanese army recruits, and the headquarters of several army units, including the 18^th Regiment, the 4^th Cavalry Brigade and the 4^th Independent Combat Engineer Regiment. Toyohashi also boasted an airfield that served the 381^st Naval Air Group, which flew Mitsubishi J2M Raiden 'Jack' single-engined interceptor fighters.

There were nine air raids on Toyohashi between January and June 1945, and in the first eight only some 25 to 30 persons were killed. These early air raids probably resulted from US bombers' attacks on Toyohashi as an alternate target or a target of opportunity. Only the ninth raid was made in concentrated strength. Starting late on the night of 19 June or just after 00.00, in the early hours of 20 June a force of 136 Boeing B-29 Superfortress four-engined heavy bombers undertook a firebombing raid on Toyohashi. The raid lasted about three hours, and ended a little before dawn. The areas primarily affected included a large part of the downtown area between Toyohashi station and the city hall, large sections of the Azumada and Maebata neighbourhoods, and neighbourhoods around Azumada elementary school.

In the aftermath of the 'Bombing of Toyohashi', the Japanese authorities compiled the following data on the damage done on the night of 19/20 June: 624 persons dead, 346 persons injured, 16,009 households affected, 68,502 people affected and 15,886 houses damaged. Among the buildings which were destroyed were five temples, the Azumada elementary school and the Kawai hospital.

In 1946, the US Army Air Forces estimated that 61.9% of the city had been destroyed.

While property damage in Toyohashi was considerable, the casualties were relatively light. This resulted in part to lessons learned from the several air raids on neighbouring Hamamatsu, which had suffered much more since its first air raid in February 1945.

On the same night, two other firebombing operations were flown elsewhere in Japan. One was against Shizuoku in neighbouring Shizuoka prefecture, and the other against Fukuoka on the island of Kyushu.