Saint Patrick's Day, while not a legal holiday in the United States, is nonetheless widely recognised and observed throughout the country as a celebration of Irish and Irish-American culture. Celebrations include prominent displays of the colour green, religious observances, numerous parades, and copious consumption of alcohol. The holiday has been celebrated in what is now the U.S since 1600, with the first parade occurring in 1601.
On Saint Patrick's Day, it is customary to wear shamrocks, green clothing or green accessories. Saint Patrick is said to have used the shamrock, a three-leaved plant, to explain the Holy Trinity to the pagan Irish. This story first appears in writing in 1726, though it may be older. In pagan Ireland, three was a significant number and the Irish had many triple deities, which may have aided St Patrick in his evangelisation efforts. Roger Homan writes, "We can perhaps see St Patrick drawing upon the visual concept of the triskele when he uses the shamrock to explain the Trinity". Patricia Monaghan says there is no evidence the shamrock was sacred to the pagan Irish. Jack Santino speculates that it may have represented the regenerative powers of nature, and was recast in a Christian context—icons of St Patrick often depict the saint "with a cross in one hand and a sprig of shamrocks in the other".
The island of Montserrat is known as the "Emerald Island of the Caribbean" because of its founding by Irish refugees from Saint Kitts and Nevis. Montserrat is one of three places where Saint Patrick's Day is a public holiday, along with Ireland and the Canadian province of Newfoundland and Labrador. The holiday in Montserrat also commemorates a failed slave uprising that occurred on 17 March 1768.
The colour green was further associated with Ireland from the 1640s, when the green harp flag was used by the Irish Catholic Confederation. Later, James Connolly described this flag as representing "the sacred emblem of Ireland's unconquered soul". Green ribbons and shamrocks have been worn on St Patrick's Day since at least the 1680s. Since then, the colour green and its association with St Patrick's Day have grown. The Friendly Brothers of St Patrick, an Irish fraternity founded in about 1750, adopted green as its colour. The Order of St Patrick, an Anglo-Irish chivalric order founded in 1783, instead adopted blue as its colour, which led to blue being associated with Saint Patrick. In the 1790s, the colour green was adopted by the United Irishmen. This was a republican organisation—founded mostly by Protestants but with many Catholic members—who launched a rebellion in 1798 against British rule. Ireland was first called "the Emerald Isle" in "When Erin First Rose" (1795), a poem by a co-founder of the United Irishmen, William Drennan, which stresses the historical importance of green to the Irish. The phrase "wearing of the green" comes from a song of the same name about United Irishmen being persecuted for wearing green. The flags of the 1916 Easter Rising featured green, such as the Starry Plough banner and the Proclamation Flag of the Irish Republic. When the Irish Free State was founded in 1922, the government ordered all post boxes be painted green, with the slogan "green paint for a green people"; in 1924, the government introduced a green Irish passport.
The first mention of Saint Patrick's Day being celebrated in Australia was in 1795, when Irish convicts and administrators, Catholic and Protestant, in the penal colony came together to celebrate the day as a national holiday, despite a ban against assemblies being in place at the time. This unified day of Irish nationalist observance would soon dissipate over time, with celebrations on Saint Patrick's Day becoming divisive between religions and social classes, representative more of Australianness than of Irishness and held intermittingly throughout the years. Historian Patrick O'Farrell credits the 1916 Easter Rising in Dublin and Archbishop Daniel Mannix of Melbourne for re-igniting St Patrick's Day celebrations in Australia and reviving the sense of Irishness amongst those with Irish heritage. The organisers of the St Patrick's festivities in the past were, more often than not, the Catholic clergy which often courted controversy. Bishop Patrick Phelan of Sale described in 1921 how the authorities in Victoria had ordered that a Union Jack be flown at the front of the St Patrick's Day parade and following the refusal by Irishmen and Irish-Australians to do so, the authorities paid for an individual to carry the flag at the head of the parade. This individual was later assaulted by two men who were later fined in court.
In England, the British Royals traditionally present bowls of shamrock to members of the Irish Guards, a regiment in the British Army, following Queen Alexandra introducing the tradition in 1901. Since 2012 the Duchess of Cambridge has presented the bowls of shamrock to the Irish Guards. While female royals are often tasked with presenting the bowls of shamrock, male royals have also undertaken the role, such as King George VI in 1950 to mark the 50th anniversary of the formation of the Irish Guards, and in 2016 the Duke of Cambridge in place of his wife. Fresh Shamrocks are presented to the Irish Guards, regardless of where they are stationed, and are flown in from Ireland.
In 1903, Saint Patrick's Day became an official public holiday in Ireland due to the Bank Holiday (Ireland) Act 1903, an act of the United Kingdom parliament introduced by Irish MP James O'Mara.
The first Saint Patrick's Day parade in Ireland was held in Waterford in 1903, hundreds of years after the first parade in North America. The week of Saint Patrick's Day 1903 had been declared Irish Language Week by the Gaelic League and in Waterford they opted to have a procession on Sunday 15 March. The procession comprised the Mayor and members of Waterford Corporation, the Trades Hall, the various trade unions and bands who included the 'Barrack St Band' and the 'Thomas Francis Meagher Band'. The parade began at the premises of the Gaelic League in George's St and finished in the Peoples Park, where the public were addressed by the Mayor and other dignitaries. On Tuesday 17 March, most Waterford businesses—including public houses—were closed and marching bands paraded as they had two days previously.
In Malaysia, the St Patrick's Society of Selangor, founded in 1925, organises a yearly St Patrick's Ball, described as the biggest Saint Patrick's Day celebration in Asia. Guinness Anchor Berhad also organises 36 parties across the country in places like the Klang Valley, Penang, Johor Bahru, Malacca, Ipoh, Kuantan, Kota Kinabalu, Miri and Kuching.
The celebrations remained low-key after the creation of the Irish Free State; the only state-organized observance was a military procession and trooping of the colours, and an Irish-language mass attended by government ministers. In 1927, the Irish Free State government banned the selling of alcohol on St Patrick's Day, although it remained legal in Northern Ireland. The ban was not repealed until 1961.
The first official, state-sponsored Saint Patrick's Day parade in Dublin took place in 1931. Public St Patrick's Day festivities in Ireland have been cancelled three times, all for public health reasons. In 2001, celebrations were postponed to May due to the foot-and-mouth outbreak, while in 2020 and 2021 they were cancelled outright due to the COVID-19 pandemic.
Saint Patrick's feast day, as a kind of national day, was already being celebrated by the Irish in Europe in the ninth and tenth centuries. Saint Patrick's feast day was finally placed on the liturgical calendar of the Catholic Church in the early 1600s, due to the influence of Waterford-born Franciscan scholar Luke Wadding. Saint Patrick's Day thus became a holy day of obligation for Catholics in Ireland. It is also a feast day in the Church of Ireland, part of the Anglican Communion. The church calendar avoids the observance of saints' feasts during certain solemnities, moving the saint's day to a time outside those periods. Saint Patrick's Day is occasionally affected by this requirement, when 17 March falls during Holy Week. This happened in 1940, when Saint Patrick's Day was officially observed on 3 April to avoid it coinciding with Palm Sunday, and again in 2008, where it was officially observed on 15 March. Saint Patrick's Day will not fall within Holy Week again until 2160. However, the popular festivities may still be held on 17 March or on a weekend near to the feast day.
It is customary for the Irish Taoiseach (Irish Prime Minister) to meet with the President of the United States on or around Saint Patrick's Day. Traditionally the Taoiseach presents the US President a Waterford Crystal bowl filled with shamrocks. This tradition began in 1952 when the Irish Ambassador to the US, John Hearne, sent a box of shamrocks to President Harry S. Truman. From then it became a yearly custom for the Irish ambassador to send Saint Patrick's Day shamrocks to an official in the US President's administration, although on some occasions the shamrocks were given personally by the Irish Taoiseach or Irish President to the US President in Washington. After the meeting between Taoiseach Albert Reynolds and President Bill Clinton in 1994, the presenting of the shamrocks became a yearly custom.
In Northern Ireland, the celebration of Saint Patrick's Day was affected by sectarian divisions. A majority of the population were Protestant Ulster unionists who saw themselves primarily as British, while a substantial minority were Catholic Irish nationalists who saw themselves primarily as Irish. Although it was a public holiday, Northern Ireland's unionist government did not officially observe St Patrick's Day. During the conflict known as the Troubles (late 1960s–late 1990s), public St Patrick's Day celebrations were rare and tended to be associated with the Catholic community. In 1976, loyalists detonated a car bomb outside a pub crowded with Catholics celebrating St Patrick's Day in Dungannon; four civilians were killed and many injured. However, some Protestant unionists attempted to 're-claim' the festival, and in 1985 the Orange Order held its own Saint Patrick's Day parade. Since the end of the conflict in 1998 there have been cross-community St Patrick's Day parades in towns throughout Northern Ireland, which have attracted thousands of spectators.
Saint Patrick's parades are now held in many locations across Japan. The first parade, in Tokyo, was organised by The Irish Network Japan (INJ) in 1992.
The first Saint Patrick's Day parade in Russia took place in 1992. Since 1999, there has been a yearly "Saint Patrick's Day" festival in Moscow and other Russian cities. The official part of the Moscow parade is a military-style parade and is held in collaboration with the Moscow government and the Irish embassy in Moscow. The unofficial parade is held by volunteers and resembles a carnival. In 2014, Moscow Irish Week was celebrated from 12 to 23 March, which includes Saint Patrick's Day on 17 March. Over 70 events celebrating Irish culture in Moscow, St Petersburg, Yekaterinburg, Voronezh, and Volgograd were sponsored by the Irish Embassy, the Moscow City Government, and other organisations.
In the mid-1990s the government of the Republic of Ireland began a campaign to use Saint Patrick's Day to showcase Ireland and its culture. The government set up a group called St Patrick's Festival, with the aims of creating a world-class national festival and "to project, internationally, an accurate image of Ireland as a creative, professional and sophisticated country with wide appeal". The first Saint Patrick's Festival was held on 17 March 1996. In 1997, it became a three-day event, and by 2006, the festival was five days long. More than 675,000 people attended the 2009 parade, and that year's festival saw almost 1 million visitors, who took part in festivities that included concerts, outdoor theatre performances, and fireworks. From 2006 to 2012 the Skyfest formed the centrepiece of the Saint Patrick's Festival.
One of the biggest celebrations outside the cities is in Downpatrick, County Down, where Saint Patrick is said to be buried. The shortest Saint Patrick's Day parade in the world formerly took place in Dripsey, County Cork. The parade lasted just 23.4 metres and traveled between the village's two pubs. The tradition began in 1999, but ended after five years when one of the pubs closed.
The Toronto Maple Leafs hockey team was known as the Toronto St. Patricks from 1919 to 1927, and wore green jerseys. In 1999, when the Maple Leafs played on Saint Patrick's Day, they wore green St Patrick's retro uniforms.
In 2004, the CelticFest Vancouver Society organised its first yearly festival in downtown Vancouver to celebrate the Celtic Nations and their cultures. This event, which includes a parade, occurs each year during the weekend nearest Saint Patrick's Day.
In Buenos Aires, a party is held in the downtown street of Reconquista, where there are several Irish pubs; in 2006, there were 50,000 people in this street and the pubs nearby. Neither the Catholic Church nor the Irish community, the fifth largest in the world outside Ireland, take part in the organisation of the parties.
Christian leaders in Ireland have expressed concern about the secularisation of Saint Patrick's Day. In The Word magazine's March 2007 issue, Fr Vincent Twomey wrote, "It is time to reclaim St Patrick's Day as a church festival". He questioned the need for "mindless alcohol-fuelled revelry" and concluded that "it is time to bring the piety and the fun together".
London, since 2002, has had an annual Saint Patrick's Day parade which takes place on weekends around the 17th, usually in Trafalgar Square. In 2008 the water in the Trafalgar Square fountains was dyed green. In 2020 the Parade was cancelled due to the COVID-19 pandemic.
In March 2009, the Calgary Tower changed its top exterior lights to new green CFL bulbs just in time for Saint Patrick's Day. Part of an environmental non-profit organisation's campaign (Project Porchlight), the green represented environmental concerns. Approximately 210 lights were changed in time for Saint Patrick's Day, and resembled a Leprechaun's hat. After a week, white CFLs took their place. The change was estimated to save the Calgary Tower some $12,000 and reduce greenhouse gas emissions by 104 tonnes.
In Quebec City, there was a parade from 1837 to 1926. The Quebec City St-Patrick Parade returned in 2010 after more than 84 years. For the occasion, a portion of the New York Police Department Pipes and Drums were present as special guests.
Astronauts on board the International Space Station have celebrated the festival in different ways. Irish-American Catherine Coleman played a hundred-year-old flute belonging to Matt Molloy and a tin whistle belonging to Paddy Moloney, both members of the Irish music group The Chieftains, while floating weightless in the space station on Saint Patrick's Day in 2011. Her performance was later included in a track called "The Chieftains in Orbit" on the group's 2012 album, Voice of Ages.
Chris Hadfield took photographs of Ireland from Earth orbit, and a picture of himself wearing green clothing in the space station, and posted them online on Saint Patrick's Day in 2013. He also posted online a recording of himself singing "Danny Boy" in space.
LGBT groups in the US were long banned from marching in Saint Patrick's Day parades in New York City and Boston, resulting in the landmark Supreme Court decision of Hurley v. Irish-American Gay, Lesbian, and Bisexual Group of Boston. In New York City, the ban was lifted in 2014, but LGBT groups still find that barriers to participation exist. In Boston, the ban on LGBT group participation was lifted in 2015.
Sarajevo, the capital city of Bosnia and Herzegovina has a large Irish expatriate community. The community established the Sarajevo Irish Festival in 2015, which is held for three days around and including Saint Patrick's Day. The festival organizes an annual a parade, hosts Irish theatre companies, screens Irish films and organizes concerts of Irish folk musicians. The festival has hosted numerous Irish artists, filmmakers, theatre directors and musicians such as Conor Horgan, Ailis Ni Riain, Dermot Dunne, Mick Moloney, Chloë Agnew and others.
Saint Patrick's Day is not a public holiday in Australia, although it is celebrated each year across the country's states and territories. Festivals and parades are often held on weekends around 17 March in cities such as Sydney, Brisbane, Adelaide, and Melbourne. On occasion, festivals and parades are cancelled. For instance, Melbourne's 2006 and 2007 Saint Patrick's Day festivals and parades were cancelled due to sporting events (Commonwealth Games and Australian Grand Prix) being booked on and around the planned Saint Patrick's Day festivals and parades in the city. In Sydney the parade and family day was cancelled in 2016 due to financial problems. However, Brisbane's Saint Patrick's Day parade, which was cancelled at the outbreak of World War II and wasn't revived until 1990, was not called off in 2020 as precaution for the COVID-19 pandemic, in contrast to many other St Patrick's Day parades around the world.
In 2017, the Russian Orthodox Church added the feast day of Saint Patrick to its liturgical calendar, to be celebrated on 30 March [O.S. 17 March].
Since 2019, the City of Waterloo, Ontario has had to contend with an ever-growing massive street party that has coincided with the Saint Patrick's Day celebrations. In 2023, police could be seen putting fences up on Ezra Avenue to discourage partiers to participate in the unauthorized event that has cost the city as much as $750,000 a year for police, paramedics, and municipal services.