The name day for Leo is celebrated on numerous dates across different countries throughout the year. Specific observances include February 19 and June 18 in Ukraine, April 11 in the USA and Denmark, and April 15 in Greece. The Nordic countries, including Finland, Norway, and Sweden, recognize June 28, while Austria and Germany observe dates in November, such as November 10.
The name Leo is a concise and highly popular masculine identifier enjoying sustained growth in the USA and ranking high across Europe. Derived from the Latin word for "lion," it inherently conveys a meaning of strength, courage, and majesty. Historically used since Roman times, its pedigree contributes to its elegant and classic tone. The name exudes a confident and charismatic mood, suggesting natural leadership and power. Leo functions almost exclusively as a male name worldwide, celebrated for its simple yet powerful structure. This combination of deep history and powerful imagery makes it a sophisticated modern choice.
| 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 |
 Greece | 18 | February | Leon, Agapitos |
 Romania | 18 | February | Leon |
| Poland | 19 | February | Arnold, Arnolf, Bądzisława, Gabin, Henryk, Konrad, Konrada, Leoncjusz, Manswet, Marceli |
| Lithuania | 20 | February | Eitvyde, Leonas, Visgintas |
| Poland | 20 | February | Euchariusz, Eustachiusz, Eustachy, Leon, Ludmiła, Ludomiła, Ostap, Siestrzewit |
| Romania | 20 | February | Leon |
 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 |
| Italy | 3 | March | Basileo |
| Romania | 3 | March | Cleonic, Eutropiu, Vasilisc |
| Hungary | 6 | March | Leonóra, Inez |
| Poland | 14 | March | Bożeciecha, Jakub, Leon, Matylda, Mechtylda, Michał |
 Czechia | 22 | March | Leona |
| Croatia | 9 | April | Marija Kleofina, Demetrije |
| Italy | 9 | April | Maria di Cleofa |
| Lithuania | 9 | April | Aurimas, Dalia, Kleopas, Rasa |
| Hungary | 11 | April | Leó, Szaniszló |
| Lithuania | 11 | April | Daugaile, Leonas, Vykintas |
| Poland | 11 | April | Filip, Herman, Jaromir, Leon, Marek |
| Poland | 15 | April | Anastazja, Bazyli, Leonid, Ludwina, Modest, Olimpia, Tytus, Wacław, Wacława, Wiktoryn, Wszegniew |
| Lithuania | 19 | April | Aiste, Eirimas, Leonas, Leontina, Simonas |
| Poland | 19 | April | Adolf, Adolfa, Adolfina, Alf, Cieszyrad, Czech, Czechasz, Czechoń, Czesław, Leon, Leontyna, Pafnucy, Tymon, Werner, Włodzimierz |
| 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 |
| Croatia | 12 | May | Leopold Mandic |
| Spain | 12 | May | Domingo, Nerea, Nereo, Aquileo, Flavia, Domitila |
| 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 | 12 | June | Antonina, Bazyli, Jan, Leon, Onufry, Wyszemir |
| 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 |
| Czechia | 19 | June | Leoš |
| Austria | 25 | June | Dorothea, Eleonora, Ella |
| France | 25 | June | Aliénor, Eléonore, Prosper, Salomon |
| Denmark | 28 | June | Eleonora |
| Poland | 28 | June | Amos, Ireneusz, Józef, Leon, Paweł, Raissa, Zbrosław |
| Spain | 30 | June | Marcial, Leonila |
| Romania | 1 | July | Cosma, Damian, Leontie |
| Poland | 3 | July | Anatol, Jacek, Korneli, Leon, Miłosław, Otto |
 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 |
| 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 |
| 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 |
| Croatia | 25 | September | Nikola of Flue, Aurelija, Kleofa, Firmin |
| Denmark | 25 | September | Cleophas |
| Lithuania | 25 | September | Aurelija, Kleopas, Ramvyde, Vaigintas |
| Poland | 25 | September | Aureli, Aurelia, Aurelian, Franciszek, Gaspar, Herkulan, Kamil, Kleofas, Kleopatra, Ładysław, Piotr, Rufus, Świętopełk, Wincenty, Władysław, Władysława, Włodzisław |
| Estonia | 28 | September | Leonhard, Lennart, Linnart, Linnar, Lenno |
| Finland | 28 | September | Arja, Lenni, Leon |
| Sweden | 28 | September | Lennart, Leonard |
| Poland | 30 | September | Grzegorz, Hieronim, Honoriusz, Imisław, Leopard, Sofia, Wera, Wiera, Wiktor, Wiktoriusz, Zofia |
| Poland | 2 | October | Dionizy, Leodegar, Stanimir, Teofil, Trofim |
| Croatia | 9 | October | Ljudevit Bertran, Dionizije, Ivan Leon |
| Lithuania | 15 | October | Domante, Gailiminas, Leonardas, Terese |
| France | 19 | October | Cléo, René |
| Greece | 19 | October | Kleopatra, Cleo |
| Lithuania | 19 | October | Geisvilas, Kantrime, Kleopatra, Laura |
| USA | 19 | October | Cleo, Cleon, Cleopatra, Howard, Howie |
| Latvia | 20 | October | Leonids, Leonija |
| Poland | 20 | October | Budzisława, Irena, Jan Kanty, Kleopatra, Wendelin, Witalis |
| 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 |
| 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 |
| Poland | 10 | November | Andrzej, Lena, Leon, Ludomir, Nelly, Nimfa, Probus, Stefan |
| Spain | 10 | November | Almudena, León |
| Austria | 15 | November | Albert, Leopold, Leopoldine |
| Croatia | 15 | November | Albert Veliki, Leopold |
| Czechia | 15 | November | Leopold |
| Denmark | 15 | November | Leopold |
| France | 15 | November | Albert, Arthur, Léopold, Malo, Victoire |
| Latvia | 15 | November | Leopolds, Lipsts, Unda, Undine |
| Lithuania | 15 | November | Albertas, Leopoldas, Vaidilas, Zadvyde |
| Poland | 15 | November | Albert, Alberta, Albertyna, Artur, Artus, Idalia, Leopold, Leopoldyna, Przybygniew, Roger |
| Slovakia | 15 | November | Leopold |
| Spain | 15 | November | Alberto, Leopoldo |
| Sweden | 15 | November | Leopold |
| USA | 15 | November | Leopold, Leopolda, Leopoldo, Leopoltine, Talia, Thalia |
| Poland | 16 | November | Aureliusz, Dionizy, Edmund, Gertruda, Leon, Marek, Maria, Niedamir, Otomar, Paweł, Piotr |
| 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 |
| Lithuania | 9 | December | Gedene, Leokadija, Vakaris, Valerija |
| Poland | 9 | December | Delfina, Joachim, Joachima, Leokadia, Loda, Waleria, Wielisława, Wiesław |
| Greece | 21 | December | Themistokleous, Ioulia, Julia, Julie |
Germany