The Matsuoka Hoyoen Sanatorium (国立療養所松丘保養園, Kokuritsuryōyōjo Matsuokahoyōen) or National Sanatorium Matsuoka Hoyoen is a sanatorium for leprosy and ex-leprosy patients situated in Aomori, Aomori, Japan that opened in 1909.

The Japanese Government promulgated the first leprosy prevention law on March 19, 1907, which took effect on April 1, 1909.

Foreigners who came into Japan after the Meiji Restoration(1868) were surprised to find leprosy patients in public areas in Japan.

The Japanese Government was worried about the many leprosy patients among those who were examined for the draft at age 20.

[1] The following table shows the number of patients held at the Sanatorium in selected years.