About 1.60 million people were living on welfare as of November, up about 46,000 from a year earlier, the Health, Labor and Welfare Ministry said Wednesday.
The increase is believed to be attributable to the graying of the population and the loss of jobs and dwellings amid the recession.
The number of people receiving public livelihood assistance is at a level last seen in the mid-1960s.
The number topped 2 million in the chaos after World War II but has stayed below 1.6 million since fiscal 1965, the year after the Tokyo Summer Olympics, a symbolic event marking Japan's postwar rehabilitation and return to the international community.
The government plans to allocate nearly ¥2.06 trillion in livelihood assistance under the fiscal 2009 budget, a record amount and up 4.7 percent from 2008.
But the government will have to increase the amount in a supplementary budget if the number requiring such assistance rises, which is seen as inevitable because it has risen every month of fiscal 2008.
The number of people requiring livelihood assistance has increased every year since fiscal 1995, after the bursting of the bubble economy.