Surname 源一 (源一 
) , all around the world, is a very rare family name. The last name 源一 is habitual in Eastern Asia, particularly China, where it is an extremely rare surname. More prevalently, 源一 is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| 源一 | China |
| 川田 源一 Japanese businessman, JP (b. 1897) |
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| 小岩井 源一 Japanese poet, JP (b. 1904) |
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