| EQUIVALENTS |
| ANCIENT GERMANIC: Chlodovech, Clodovicus, Hludowig, Ludovicus |
| BASQUE: Koldobika |
| BRETON: Loïc |
| CATALAN: Lluís |
| CROATIAN: Alojz, Alojzije |
| CZECH: Alois, Ludvík |
| DANISH: Ludvig |
| DUTCH: Lodewijk, Louis |
| ENGLISH: Aloysius, Lewis, Louis |
| ESPERANTO: Ludoviko |
| FRENCH: Loïc, Louis, Ludovic |
| GALICIAN: Lois |
| GERMAN: Alois |
| HUNGARIAN: Alajos, Lajos |
| ICELANDIC: Lúðvík |
| IRISH: Alaois |
| ITALIAN: Aloisio, Alvise, Lodovico, Ludovico, Luigi |
| LATVIAN: Ludis, Ludvigs |
| LITHUANIAN: Liudvikas |
| MEDIEVAL OCCITAN: Aloys, Aloysius |
| NORWEGIAN: Ludvig |
| OCCITAN: Loís |
| POLISH: Alojzy, Ludwik |
| PORTUGUESE (BRAZILIAN): Luiz |
| PORTUGUESE: Aloísio, Luís |
| SLOVAK: Alojz |
| SLOVENE: Alojz, Alojzij, Ludvik |
| SPANISH: Luis |
| SWEDISH: Ludvig |
|
| DIMINUTIVES AND SHORT FORMS |
| ANCIENT GERMANIC: Clovis |
| BASQUE: Koldo |
| CZECH: Luděk |
| DUTCH: Lowie, Ludo |
| ENGLISH: Lou, Louie |
| ESPERANTO: Luĉjo |
| FRENCH: Clovis, Lou |
| GERMAN: Lutz |
| ITALIAN: Gino, Luigino, Vico |
| PORTUGUESE: Luisinho |
| SLOVENE: Lojze |
| SPANISH: Lucho |
| SWEDISH: Love, Ludde |
|
| FEMININE FORMS |
| CROATIAN: Alojzija |
| DANISH: Louise, Lovise |
| DUTCH: Loes, Louisa, Louise |
| ENGLISH: Lou, Louella, Louisa, Louise, Luella, Lula |
| ESTONIAN: Loviise |
| FINNISH: Loviisa |
| FRENCH: Lou, Louise, Louisette |
| GERMAN: Aloisia, Louisa, Luise, Lulu |
| GREEK: Louiza |
| HUNGARIAN: Lujza |
| ITALIAN: Gina, Ludovica, Luigia, Luigina, Luisa, Luisella |
| LITHUANIAN: Liudvika |
| MAORI: Ruiha |
| NORWEGIAN: Lovise |
| POLISH: Ludwika, Luiza |
| PORTUGUESE: Luísa, Luiza |
| ROMANIAN: Luiza |
| SLOVAK: Alojzia |
| SLOVENE: Alojzija |
| SPANISH: Luisa, Luisina, Luisita |
| SWEDISH: Louise, Lovisa |
|
| OTHER FORMS |
| VARIOUS: Ouida |
|