The 1968 Hyūga-nada earthquake (Japanese: 1968年日向灘地震) occurred on April 1 at 09:42 local time.

The earthquake had a magnitude of Mw 7.5, and the epicenter was located in Hyūga-nada Sea, off the islands of Kyushu and Shikoku, Japan.

The subduction interface around this region passes southwestwards from the Nankai megathrust to the Ryukyu Trench just south of Kyusyu.

[6] This earthquake is the strongest event recorded in the Hyūga-nada Sea region.

The maximum slip was estimated to be 4 m.[7] It was estimated that, in the Hyūga-nada Sea region, earthquakes with magnitudes about 7.6 occur with a period of about 200 years, while earthquakes with magnitudes about 7.1 occur with a period of about 20 to 27 years.