This page lists 27 holidays that start with O, from “Oak Apple Day” to “Otago Anniversary Day”. They include religious festivals, national days, harvest celebrations, and memorial days from many parts of the world. You can use the list to plan travel around local events, find ideas for classroom lessons, or learn how different cultures mark important moments.
Holidays are special days set aside to celebrate, remember, or honor a person, event, or belief. Some are very old, like Japan’s “Obon,” which has honored ancestral spirits for centuries, while others, like “Orange Shirt Day,” are much newer.
Below you’ll find the table with the holiday name, date, country or region, traditions, and description for each entry.
Holiday: the name of the celebration, so you can quickly spot the one you want and tell similar-sounding events apart.
Date: when the holiday takes place, including fixed dates and moveable ones, so you know when to plan, travel, or take part.
Country/Region: where the holiday is observed, which helps you see whether it is local, national, or celebrated across several countries.
Traditions: the main customs, foods, and activities people enjoy, giving you a quick picture of what you would see or do on the day.
Description: a short summary of the holiday’s origin and meaning, so you understand why people celebrate it and what it stands for.
Holidays
| Holiday | Date | Country/Region | Traditions |
|---|---|---|---|
| Oak Apple Day | May 29 | England, UK | Wearing oak leaves or sprigs, flying flags, and some village parades |
| Obon | Mid-August (July in some regions) | Japan | Lighting lanterns, Bon Odori folk dances, visiting family graves, and floating lanterns |
| Ohi Day | October 28 | Greece, Cyprus | Military and school parades, flying Greek flags, and patriotic speeches |
| Oktoberfest | Mid-to-late September through the first Sunday of October | Munich, Germany | Beer tents, traditional costumes (dirndl and lederhosen), brass bands, pretzels, and roast chicken |
| Onam | Late August to mid-September (Malayalam month of Chingam) | Kerala, India | Pookalam flower carpets, the Onasadya feast served on banana leaves, snake boat races, and Kathakali dance |
| Orthodox Christmas | January 7 | Russia, Serbia, Ethiopia, Georgia, and other Orthodox countries | Midnight church services, Nativity fast ending, family feasts, and caroling |
| Orthodox Easter | Moveable (April or May, calculated by the Julian calendar) | Greece, Russia, Serbia, Romania, Ethiopia, and other Orthodox countries | Midnight Resurrection service, candlelight processions, red-dyed eggs, and lamb feasts |
| Orthodoxy Sunday | First Sunday of Great Lent (moveable) | Eastern Orthodox countries | Church processions carrying icons and special liturgy |
| Ostara | Around March 20 (spring equinox) | Germanic and Neopagan communities, Europe, North America | Decorated eggs, spring flowers, bonfires, and symbols of renewal such as hares |
| Olsok | July 29 | Norway, Faroe Islands | Bonfires, church services, and folk gatherings |
| Omisoka | December 31 | Japan | Eating toshikoshi soba noodles, house cleaning, and temple bells rung 108 times |
| Oshogatsu | January 1-3 | Japan | Visiting shrines (hatsumode), eating osechi ryori, sending nengajo cards, and giving otoshidama money to children |
| Orange Shirt Day | September 30 | Canada | Wearing orange shirts, school lessons, and memorial events |
| Orangemen’s Day | July 12 | Northern Ireland, Scotland, Canada, Ghana | Marching bands, colorful sashes, and parades led by the Orange Order |
| Olympic Day | June 23 | Worldwide | Community sports events, fun runs, and school activities |
| Okinawa Memorial Day | June 23 | Okinawa, Japan | Moments of silence, memorial ceremonies, and wreath laying at Mabuni Hill |
| Oruro Carnival | February or March (before Lent) | Oruro, Bolivia | Devil dances (Diablada), colorful masks, brass bands, and a three-day parade |
| Ogoh-Ogoh Parade | Eve of Nyepi (March) | Bali, Indonesia | Carrying giant demon statues through the streets and burning them at night |
| Osun-Osogbo Festival | August | Osogbo, Nigeria | Processions, drumming, offerings at the Osun river, and prayers to the goddess Osun |
| Oeshiki | October 12-13 | Japan | Lantern processions, drumming, chanting, and paper cherry blossom floats |
| Odunde Festival | Second Sunday of June | Philadelphia, United States | African-inspired music, street market, food vendors, and a procession to the river |
| October Revolution Day | November 7 | Russia, former Soviet republics | Military parades (in Soviet times), wreath laying, and communist party gatherings |
| Oman National Day | November 18 | Oman | Parades, fireworks, decorated streets, and flag displays |
| Old Christmas | January 6 | England, Appalachian United States, Ireland | Church services, wassailing, and Twelfth Night customs |
| Old New Year | January 13-14 | Russia, Ukraine, Serbia, Belarus | Family dinners, fireworks, and a second round of New Year toasts |
| Opening Day | Late March or early April | United States, Canada | Ceremonial first pitches, pregame flyovers, tailgating, and ballpark hot dogs |
| Otago Anniversary Day | March 23 (observed on the nearest Monday) | Otago, New Zealand | Regional events, picnics, and community gatherings |
Descriptions
Oak Apple Day
Marks the restoration of King Charles II to the throne in 1660. It also recalls his escape from Parliamentarian soldiers by hiding in an oak tree. Once a major public holiday, it survives in a few local customs.
Obon
A Buddhist festival honoring the spirits of ancestors, who are believed to return home for a few days. Families reunite, clean graves, and dance to welcome and send off the spirits.
Ohi Day
Commemorates Greece’s one-word “No” (Ohi) to Italy’s ultimatum in 1940, which pulled the country into World War II. It is a national holiday celebrated with parades and flag displays.
Oktoberfest
The world’s largest beer festival began in 1810 as a royal wedding celebration. Millions of visitors now gather in Munich each year for beer, food, music, and carnival rides.
Onam
Kerala’s biggest harvest festival celebrates the legendary return of King Mahabali. Ten days of festivities include elaborate flower designs, a large vegetarian feast, and boat races.
Orthodox Christmas
Celebrated by churches that follow the Julian calendar, which puts Christmas Day on January 7 in the modern calendar. Many families keep a fast beforehand and gather for a festive meal afterward.
Orthodox Easter
The most important holiday in Eastern Orthodox Christianity, celebrating the resurrection of Jesus. It often falls on a different date from Western Easter because of the calendar difference.
Orthodoxy Sunday
Observed on the first Sunday of Lent to celebrate the restoration of icons in 843 after the Byzantine iconoclasm. Congregations carry icons in procession and recite prayers.
Ostara
A modern pagan celebration of the spring equinox, named after the Germanic goddess Eostre. It is tied to themes of fertility and rebirth and is a likely source of some Easter customs.
Olsok
Also called St. Olaf’s Day, it honors King Olaf II of Norway, who died at the Battle of Stiklestad in 1030. Norway’s patron saint is remembered with bonfires and church services.
Omisoka
Japan’s New Year’s Eve is a time to clean the house and finish the year’s business. Families eat buckwheat noodles for long life and listen as temple bells ring 108 times at midnight.
Oshogatsu
Japan’s New Year celebration is the country’s most important holiday. Businesses close for several days while families visit temples and shrines and share traditional foods.
Orange Shirt Day
Honors survivors of Canada’s residential school system and remembers the children who never returned home. It began in 2013 and became the National Day for Truth and Reconciliation, a federal holiday, in 2021.
Orangemen’s Day
Also known as the Twelfth, this holiday marks the Protestant victory of William of Orange at the Battle of the Boyne in 1690. Parades are held across Northern Ireland, and the day remains politically sensitive.
Olympic Day
Celebrates the founding of the International Olympic Committee in 1894. National Olympic committees organize sporting events to encourage people of all ages to try new activities and be active.
Okinawa Memorial Day
Remembers the lives lost in the 1945 Battle of Okinawa, one of the deadliest battles of World War II. A ceremony is held each year at the Peace Memorial Park in Itoman.
Oruro Carnival
A UNESCO-recognized festival combining Andean traditions with Catholic belief. Thousands of dancers in elaborate costumes parade for hours through Oruro, honoring the Virgin of the Mineshaft.
Ogoh-Ogoh Parade
On the night before Nyepi, the Balinese Day of Silence, villagers parade huge papier-mache demons to drive away evil spirits. The statues are burned at the end of the evening.
Osun-Osogbo Festival
A two-week Yoruba festival honoring the river goddess Osun in a UNESCO-listed sacred grove. Visitors and devotees gather for ceremonies, music, and offerings meant to bring fertility and prosperity.
Oeshiki
Commemorates the death of Nichiren, the founder of Nichiren Buddhism. The largest observance is at Ikegami Honmonji temple in Tokyo, where thousands carry lanterns and chant at night.
Odunde Festival
One of the largest African American street festivals in the country, it began in 1975 and draws on the Yoruba new year tradition. Participants offer fruit and flowers to the Schuylkill River.
October Revolution Day
Commemorates the 1917 Bolshevik Revolution. It was a major Soviet holiday with large parades, but in Russia the public holiday was replaced in 2005 and it is now marked mostly by communist groups.
Oman National Day
Celebrates the founding of Oman’s modern state and the birthday of Sultan Qaboos, the late ruler. People decorate cars and buildings, and the country holds military displays and public festivities.
Old Christmas
The older date of Christmas, linked to the 1752 switch to the Gregorian calendar, which skipped 11 days. Some communities still observe it as a day of quiet celebration and local folk traditions.
Old New Year
Marks the start of the new year by the old Julian calendar. Many people in former Soviet and Orthodox countries celebrate again, with gatherings and festive meals a couple of weeks after January 1.
Opening Day
The first day of the Major League Baseball regular season is treated as an unofficial holiday by fans. Many people take the day off to attend games and celebrate the return of baseball.
Otago Anniversary Day
A regional public holiday marking the founding of the Otago settlement by Scottish colonists in 1848. It is observed in the Otago region, around Dunedin, on the Monday closest to March 23.