| La Mónica | La Pierre (de) |
| La Tour (de) | Lagger |
| Lambiel | Lambien |
| Lambrigger | Lamon |
| Lampert | Landry |
| Lang | Lange |
| Langmatter | Lanwer |
| Largey | Larzay |
| Latapie | Lateldint |
| Lathion | Lattion |
| Laub | Lauber |
| Launaz | Laurenti |
| Lauwiner | Lavallaz (de) |
| Léger | Lehner |
| Leibu | Leigginer |
| Leitzinger | Lener |
| Lengen | Lenzser |
| Leopold | Lergien |
| Lettingue | Leuk (von) |
| Leuzinger | Levet |
| Levrand | Leya |
| Levdier | Liand |
| Liaudet | Liddes de Liebhauser |
| Liettei | Ligato |
| Livioz | Lob |
| Locatelli | Locher |
| Lochmann | Lochmatter |
| LoEs (de) | Loesch |
| Logean | Loges (des) |
| Lomazzi | Lonfat |
| Lorenz | Loretan |
| Loscho | Lötscher |
| Lovay | Lovey |
| Lovina (de) | Lovisa |
| Lowiner | Loy |
| Loye | Lucianaz |
| Luder | Luder |
| Luggen | Lugon |
| Lugon-Moulin | Luisier |
| Luiter | Lütolf |
| Luyet | Luyter |
| Luyter |