| Jacopo | | YAH-ko-po | Italian | |
| Jessica | | JES-i-kə (English) | English, French, German, Swedish, Norwegian, Danish, Italian, Spanish, Portuguese | |
| Jolanda | | yo-LAHN-dah (Dutch, Italian) | Dutch, Slovene, Croatian, Italian | |
| Ladislao | | - | Italian | |
| Lamberto | | lahm-BER-to | Italian | |
| Lapo | | - | Italian | |
| Lara (1) | | LAHR-ə (English), LAH-rah (German, Italian, Spanish, Portuguese) | Russian, English, German, French, Italian, Spanish, Portuguese, Dutch, Hungarian, Slovene, Croatian | |
| Laura | | LAWR-ə (English), LOW-rah (Spanish, Italian, Finnish, Polish, Swedish, Norwegian, Danish, German, Dutch), LAW-oo-raw (Hungarian) | English, Spanish, Italian, Portuguese, Romanian, Finnish, Estonian, Hungarian, Polish, Slovene, Croa | |
| Lauretta | | - | Italian | |
| Lauro | | - | Italian | |
| Lazzaro | | LAHD-dzah-ro | Italian | |
| Leandra | | le-AHN-drah (Spanish) | Portuguese, Spanish, Italian | |
| Leandro | | le-AHN-dro (Spanish) | Spanish, Portuguese, Italian | |
| Lelia | | - | Italian | |
| Lelio | | - | Italian | |