Leon's name day is observed across multiple dates and countries throughout the year. The celebrations start in February (Greece, Poland) and continue through March and April (Poland, USA, Spain). Mid-year observances fall in June (Poland, Ukraine, Norway) and July (Poland). The calendar concludes with name days in September (Finland) and November (France, Poland, Spain).
Leon is a distinctly male name derived from the Greek word for "lion," immediately lending it connotations of strength, regality, and courage. Historically, the name gained widespread European adoption due to its powerful simplicity and ancient roots. In the USA, Leon enjoyed significant peak popularity early in the 20th century and has recently seen a strong resurgence, confirming its status as a cosmopolitan favorite. The overall mood of the name is one of classic elegance and quiet confidence. This short, robust name successfully combines timelessness with modern accessibility.
| Country | Day | Month | Names |
 Greece | 18 | February | Leon, Agapitos |
 Poland | 20 | February | Euchariusz, Eustachiusz, Eustachy, Leon, Ludmiła, Ludomiła, Ostap, Siestrzewit |
| Poland | 14 | March | Bożeciecha, Jakub, Leon, Matylda, Mechtylda, Michał |
| Poland | 11 | April | Filip, Herman, Jaromir, Leon, Marek |
 USA | 11 | April | Alger, Algernon, Ari, Ariel, Arielle, Arion, Leo, Leon, Leonel, Leona, Leontine, Lionel |
| Poland | 19 | April | Adolf, Adolfa, Adolfina, Alf, Cieszyrad, Czech, Czechasz, Czechoń, Czesław, Leon, Leontyna, Pafnucy, Tymon, Werner, Włodzimierz |
| Poland | 12 | June | Antonina, Bazyli, Jan, Leon, Onufry, Wyszemir |
 Ukraine | 18 | June | Leon, Leo |
 Norway | 28 | June | Lea, Leo, Leon |
| Poland | 28 | June | Amos, Ireneusz, Józef, Leon, Paweł, Raissa, Zbrosław |
| Poland | 3 | July | Anatol, Jacek, Korneli, Leon, Miłosław, Otto |
| Poland | 17 | July | Aleksander, Aleksy, Andrzej, Bogdan, Dzierżykraj, Januaria, Julietta, Leon, Marceli, Marcelina, Maria Magdalena |
| Poland | 20 | July | Czech, Czechasz, Czechoń, Czesław, Eliasz, Heliasz, Hieronim, Leon, Małgorzata, Paweł, Sewera |
 Finland | 28 | September | Arja, Lenni, Leon |
| Poland | 10 | November | Andrzej, Lena, Leon, Ludomir, Nelly, Nimfa, Probus, Stefan |
| Poland | 16 | November | Aureliusz, Dionizy, Edmund, Gertruda, Leon, Marek, Maria, Niedamir, Otomar, Paweł, Piotr |
| Country | Day | Month | Names |
 Hungary | 4 | January | Titusz, Leona, Angel |
| Poland | 4 | January | Angelika, Aniela, Benedykta, Benita, Dobromir, Dobrymir, Eugeniusz, Grzegorz, Izabela, Leonia, Rygobert, Tytus |
 Austria | 10 | January | Leonie, Paulus, Wilhelm |
| Poland | 13 | January | Bogumił, Bogusąd, Bogusława, Godfryd, Gotfryd, Leoncjusz, Melania, Weronika |
 Italy | 14 | January | Leonzio, Llario di Poitiers |
 Lithuania | 17 | January | Beatrice, Dovainis, Leonile, Vilda |
| Lithuania | 28 | January | Gedautas, Leonidas, Nijole |
| Poland | 28 | January | Agnieszka, Augustyn, Flawian, Ildefons, Julian, Karol, Leonidas, Piotr, Radomir, Roger, Waleriusz |
| Poland | 19 | February | Arnold, Arnolf, Bądzisława, Gabin, Henryk, Konrad, Konrada, Leoncjusz, Manswet, Marceli |
| Lithuania | 20 | February | Eitvyde, Leonas, Visgintas |
 Croatia | 21 | February | Petar, Damir, Eleonora |
| Hungary | 21 | February | Eleonóra |
 Latvia | 21 | February | Eleonora |
| Lithuania | 21 | February | Eleonora, Feliksas, Kestutis, Zemyna |
| Poland | 21 | February | Eleonora, Feliks, Fortunat, Kiejstut, Teodor, Wyszeniega |
 Slovakia | 21 | February | Eleonóra |
 Spain | 22 | February | Margarita, Leonor |
| Poland | 27 | February | Aleksander, Anastazja, Auksencjusz, Gabriel, Gabriela, Honoryna, Leander, Leonard, Sierosława |
| Austria | 1 | March | Albin, Leontina, Roger |
| Greece | 3 | March | Kleonikos |
| Hungary | 6 | March | Leonóra, Inez |
 Czechia | 22 | March | Leona |
| Lithuania | 11 | April | Daugaile, Leonas, Vykintas |
| Greece | 15 | April | Leonidas, Leo |
| Poland | 15 | April | Anastazja, Bazyli, Leonid, Ludwina, Modest, Olimpia, Tytus, Wacław, Wacława, Wiktoryn, Wszegniew |
| Lithuania | 19 | April | Aiste, Eirimas, Leonas, Leontina, Simonas |
| Spain | 19 | April | León, Crescencio |
| Austria | 22 | April | Alfred, Kaj, Leonidas |
| Lithuania | 22 | April | Leonas, Leonidas, Norvaide, Visgailas |
| Poland | 22 | April | Heliodor, Kajus, Leonia, Leonid, Łukasz, Soter, Strzeżymir, Teodor |
| USA | 22 | April | Caia, Caissa, Kai, Kaila, Kailey, Kaleigh, Kaley, Kay, Kayla, Kaylee, Kayleigh, Kayley, Kaylie, Kaylin, Kaylyn, Leonidas, Makayla, Mckayla |
| Spain | 24 | April | Leoncio, Honorio, Honoria, Fidel |
| Latvia | 23 | May | Leontine, Ligija, Lonija |
| Poland | 23 | May | Budziwoj, Dezyderiusz, Dezydery, Emilia, Iwona, Jan, Leontyna, Michał, Symeon |
| Lithuania | 27 | May | Augustinas, Brunonas, Leonora, Virgaudas, Zymante |
| Poland | 15 | June | Abraham, Angelina, Bernard, Jolanta, Leona, Leonida, Nikifor, Wit, Witold, Witołd, Witolda, Witosław, Wodzisław |
 Denmark | 18 | June | Leontius |
 France | 18 | June | Léonce |
| Poland | 18 | June | Efrem, Elżbieta, Gerwazy, Leonia, Marek, Marina, Paula |
| Austria | 25 | June | Dorothea, Eleonora, Ella |
| France | 25 | June | Aliénor, Eléonore, Prosper, Salomon |
| Denmark | 28 | June | Eleonora |
| Spain | 30 | June | Marcial, Leonila |
 Estonia | 8 | July | Ellinor, Eleonoora, Leonoora, Loora, Loore, Noora, Nora |
| Lithuania | 9 | July | Algirdas, Algirde, Leonardas, Veronika |
| Finland | 11 | July | Elli, Noora, Nelli, Eleonoora, Elea |
| Latvia | 11 | July | Leonora, Lore, Svens, Varaidotis |
 Sweden | 11 | July | Eleonora, Ellinor |
| Austria | 27 | July | Berthold, Natalie, Pantaleon |
| Poland | 27 | July | Alfons, Alfonsyna, Aureli, Julia, Laurenty, Lilla, Marta, Natalia, Natalis, Pantaleon, Rudolf, Rudolfa, Rudolfina, Wszebor |
| Poland | 28 | July | Innocenta, Innocenty, Marcela, Pantaleon, Samson, Świętomir, Wiktor, Wiktoriusz |
| Ukraine | 8 | August | Amelia, Amilian, Emil, Emily, Fedir, Theodore, Leonid |
| Poland | 12 | August | Bądzisław, Hilaria, Klara, Lech, Leonida, Piotr |
| Lithuania | 15 | August | Napalys, Napoleonas, Sigita, Visvilas, Vydene |
| Poland | 15 | August | Maria, Napoleon, Stefan, Stella, Trzebimir |
| USA | 15 | August | Madonna, Malia, Mara, Maria, Mariah, Marian, Mariana, Maribel, Marie, Marisa, Marissa, Maritza, Marla, Mary, Maryann, Mimi, Miriam, Mitzy, Molly, Napoleon, Polly |
| Slovakia | 16 | August | Leonard |
| USA | 18 | August | Aileen, Eileen, Elaina, Elaine, Eleanor, Elena, Eliana, Ella, Elle, Ellen, Ellie, Helen, Helena, Iliana, Lena, Leonora, Nell, Nellie, Nelly |
| USA | 25 | August | Dorcas, Lanard, Lennie, Lenny, Leonard, Leonardo, Tabatha, Tabitha |
| Estonia | 28 | September | Leonhard, Lennart, Linnart, Linnar, Lenno |
| Sweden | 28 | September | Lennart, Leonard |
| Croatia | 9 | October | Ljudevit Bertran, Dionizije, Ivan Leon |
| Lithuania | 15 | October | Domante, Gailiminas, Leonardas, Terese |
| USA | 19 | October | Cleo, Cleon, Cleopatra, Howard, Howie |
| Latvia | 20 | October | Leonids, Leonija |
| Ukraine | 1 | November | Kuzma, Leonard |
| Austria | 6 | November | Christine, Leonhard, Rudolf |
| Croatia | 6 | November | Leonard pust., Vedran, Sever |
| Denmark | 6 | November | Leonhardus |
| France | 6 | November | Bertille, Léonard |
| Greece | 6 | November | Leonardo |
| Italy | 6 | November | Leonardo di Noblac |
| Latvia | 6 | November | Leo, Leonards, Leonhards, Leons, Linards |
| Lithuania | 6 | November | Asmantas, Leonardas, Vygaude |
| Norway | 6 | November | Lennart, Leonard |
| Poland | 6 | November | Feliks, Leonard, Trzebowit, Ziemowit |
| Spain | 6 | November | Leonardo |
| Croatia | 10 | November | Leon Veliki papa, Lavoslav, Lav |
| France | 10 | November | Léon, Noé |
| Italy | 10 | November | Leone I Magno |
| Lithuania | 10 | November | Andrius, Galvyde, Leonas, Vaisviltas |
| Spain | 10 | November | Almudena, León |
| Croatia | 26 | November | Konrad, Leonardo, Dubravko |
| Poland | 26 | November | Delfin, Dobiemiest, Jan, Konrad, Konrada, Lechosław, Lechosława, Leonard, Sylwester |
| Poland | 27 | November | Damazy, Dominik, Leonard, Maksymilian, Oda, Stojgniew, Walery, Wirgiliusz |