The Sasebo Line is a railway line in Kyushu, Japan, operated by the Kyushu Railway Company. It connects Kōhoku Station in Kōhoku, Saga Prefecture to Sasebo Station in Sasebo, Nagasaki Prefecture. It is part of the route connecting Sasebo with Saga and Fukuoka. Most of the line runs parallel to National Routes 34 and 35. From 1898 to 1934 the Kōhoku - Haiki section was part of the original Nagasaki Main Line.

The Kyushu Railway Company, also referred to as JR Kyushu , is one of the seven constituent companies of Japan Railways Group. It operates intercity rail services within Kyushu, Japan and the JR Kyushu Jet Ferry Beetle hydrofoil service across the Tsushima Strait between Fukuoka and Busan, South Korea. It also operates hotels, restaurants, and drugstores across its service region. JR Kyushu's headquarters are in Hakata-ku, Fukuoka.