Leon's name day is observed across numerous countries throughout the year. Celebrations often occur multiple times in a single country, reflecting different regional or saintly associations. Poland has the highest frequency of observance, noting dates such as February 20, March 14, and November 10. Key international dates include February 18th in Greece and Romania, April 11th in the USA, and June 28th in Norway and Ukraine. The calendar highlights the name's broad historical significance across Eastern and Western Europe.
Leon is a classically rooted male name, popular globally and known for its enduring strength. Derived from the ancient Greek word *leōn*, the name inherently signifies the powerful traits of the lion, such as courage and royalty. It has a rich history, being frequently used across European royalty and early Christian figures, lending it a sophisticated air. In the USA, it was highly popular in the early 1900s and remains a sturdy, traditional choice today. The name projects a mood that is simultaneously strong, solid, and elegantly timeless. Leon is universally identified as a male given name across all major regions.
| Country | Day | Month | Names |
 Greece | 18 | February | Leon, Agapitos |
 Romania | 18 | February | Leon |
 Poland | 20 | February | Euchariusz, Eustachiusz, Eustachy, Leon, Ludmiła, Ludomiła, Ostap, Siestrzewit |
| Romania | 20 | February | Leon |
| 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 |
| Romania | 3 | March | Cleonic, Eutropiu, Vasilisc |
| 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 |
| Romania | 18 | June | Ipatie, Leontie, Teodul |
| Austria | 25 | June | Dorothea, Eleonora, Ella |
| France | 25 | June | Aliénor, Eléonore, Prosper, Salomon |
| Denmark | 28 | June | Eleonora |
| Spain | 30 | June | Marcial, Leonila |
| Romania | 1 | July | Cosma, Damian, Leontie |
 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 |