Shakai Taishuto

nihongo|Socialist Masses Party|社会大衆党|Shakai Taishutō was a moderate leftist political party in early Showa period Japan.

The Shakai Taishutō was founded by Abe Isoo in July 1932, as a merger of the Shakai Minshuto with the Zenkoku Rono Taishuto (National Labor-Farmer Masses Party). In a period of increasing extremism in politics, the new party attempted to maintain a middle-of-the road approach, which inevitably resulted in a confused policy.

On one hand, it pushed for improvement in the lot of the farmers by cutting the military budget; on the other hand, it supported Japanese aggression in Manchuria. It advocated increased international cooperation and opposed Japan's withdraw from the League of Nations, but at the same time supported the invasion of China in 1937.

It was the only leftist party allowed to function in the 1930s, it grew increasing nationalistic and militaristic, but was absorbed into the Imperial Rule Assistance Association in 1940.