Family name لوثر (Luther 
, Lotar 
, لوثر 
) , across the world, is a common cognomen. The surname لوثر is characteristic of Marshall Islands, where it is quite a common surname, Seychelles, and Germany, where it is quite a rare surname. In absolute terms, it is commonest in the United States, Germany, and Indonesia. Also, لوثر is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Luther | Germany, Indonesia, Philippines, United States, Democratic Republic of the Congo |
| Lotar | Germany, Indonesia, Philippines, United States, India |
| لوثر | Iraq |
| Lothair | Germany, Philippines, Mexico, United States, France |