In the Catholic Church, several locations around the world invoke the patronage of the Immaculate Conception. Catholic diocesan authorities with the expressed and written approval of the Pope in countries including the United States, Brazil, Korea, the Philippines and Spain designate the Blessed Virgin Mary as their principal patroness.
As part of the patronage, the Feast of the Immaculate Conception is often observed both religiously and culturally within these countries. Numerous national parades, processions and cultural festivities are associated with this patronage ranging from public holidays to holy day of obligation. Several Popes have conferred this title of patronage, sometimes initiated by bishops.
The list below enumerates the various countries by which the Pope, through a papal bull has formally granted the Immaculate Conception as the patroness of the people and its land or kingdom.
The list of Pontifical declaration does not include Ireland, Nicaragua and Portugal.
On 13 May 1846, the United States bishops unanimously chose “the Virgin Mary, conceived without Sin”, as patroness of the country, a decision approved by Pope Pius IX on February 7 of the following year and published in a decree of 2 July 1847.
On 10 April 1848, a voting process and discussion was made on the regularisation of the rubrics for the Feast of the Immaculate Conception to be celebrated in that country. By 1849, this decree was published at the 7th Provincial Council of Baltimore. The decrees were signed and witnessed by Cardinal Giacomo Filippo Fransoni.
On 8 July 1914, Pope Pius X sent an apostolic letter to Archbishop of Baltimore Cardinal James Gibbons approving the patronage of the Immaculate Conception for the new construction site of the National Shrine of the Immaculate Conception.
On 10 April 1919, Pope Benedict XV reiterated this patronage and stated that he had ordered a mosaic of Our Lady of the Immaculate Conception to be made in the Vatican Mosaic Studio for the shrine's high altar.
In 1923, Pope Pius XI chose a mosaic version of Bartolomé Esteban Murillo's La Purísima Inmaculada Concepción for installation at the shrine, the image is a mosaic rendition of the venerated Immaculate Conception enshrined at the Royal Palace of Aranjuez.  now installed in the largest Roman Catholic church in the United States of America.
On 22 August 2013, Pope Benedict XVI granted a Pontifical decree of Canonical coronation towards a venerated Marian image in Louisiana bearing the same patronal title.
The Blessed Virgin Mary is the official Patroness of Brazil under the localized title Our Lady of Aparecida (Our Lady of Immaculate Conception (who) Appeared).
Amidst Christian suspicion and persecution at the time, Pope Gregory XVI invested ecclesiastical interest in strengthening the first bishopric in Korea. In 1831, he established the first and only Apostolic Vicariate in Korea which survived no foreign Catholic priests since the anti-Catholic persecutions that went on earlier that year. According to Cardinal Nicolas Cheong Jin-suk, in 1841, Pope Gregory XVI solemnly dedicated the Korean Catholic Church to the Virgin Mary under the title "Immaculate Virgin".
On 6 May 1984, Pope John Paul II reiterated this patronage by entrusting the Republic of Korea to the Virgin Mary, given at the Myeong-dong Cathedral of the Immaculate Conception in Seoul, Korea. In the Apostolic Letter, John Paul II noted that Bishop Imbert Bum first consecrated Korea to the Immaculate Conception in 1837, followed by Bishop Jean Joseph Ferréol in 1846 along with Saint Joseph as its co-patron in the village of Surich’igol, nearby the city of Gongju. According to the papal brief, a similar re-dedication of patronage to the Immaculate Conception was invoked on by the French Bishop Gustave Charles Mutel (1854-1933) on 29 May 1898, when the cathedral was ceremoniously opened to the Korean public.
Among various fiestas and rituals honouring the Immaculate Conception's patronage is the annual Grand Marian Procession in Manila, where various statues of the Virgin Mary depicting her different titles and apparitions are borne in procession. The images are removed from their respective shrines and brought around the Spanish colonial capital district of Intramuros towards Manila Cathedral, which is dedicated to the Immaculate Conception. The event is administered both by the Cofradía de la Inmaculada Concepción and the Intramuros Administration, in cooperation with the City Government of Manila and the Roman Catholic Archdiocese of Manila. To date, four venerated Marian images with the patronal title in the Philippines have been granted a decree of Canonical Coronation by a Pope.
The Philippines celebrated the 1954 Marian year by releasing a commemorative stamp featuring an image of the Immaculate Conception, and re-printed again in 1958. On 29 March 2017, the Philippine government through the House of Representatives approved Bill # 5241 declaring December 8 as a non-working official holiday, and was officially signed into constitutional law on 23 December 2017 under Republic Act No. 10966 by President Rodrigo Duterte in honor of the Blessed Virgin Mary as patroness of its country.
By Papal decree, the Immaculate Conception alone is the universal and national patroness of Spain, by virtue of a papal mandate issued by Pope Clement XIII on 8 November 1760, while Saint James the Greater remains, the same pope declared, the primary patron of the Spanish people. The feast of the Immaculate Conception is also one of the nine national and public holidays and a holy day of obligation.
The patronage settles the dispute between a heated religious debate during the mid 1600s, when followers of the mythical figure Saint James Matamoros wished to impose him as the national patron saint versus the followers of Saint Teresa of Avila.
On 11 September 1759, the elected members of the Spanish Cortes petitioned King Charles III of Spain to request from the pope the "universal patronage of Our Lady of the Immaculate Conception in all the Kingdoms of Spain and the Indies".
With the papal bull Quantum ornamenti of 8 November 1760, Pope Clement granted the request of King Charles III, declaring the Virgin Mary, under the title of the Immaculate Conception, patroness of the whole of the Kingdom of Spain along with its eastern and western territories, (in the Americas and the Philippines).
In another document, Pope Clement granted that the Spanish clergy could celebrate the Mass and the Liturgy of the Hours on the feast and its octave with the texts used by the Franciscans rather than that in the Tridentine Roman Missal and Roman Breviary as revised by Pope Pius V, which did not attach the adjective "Immaculate" to the phrase "Conception of the Blessed Virgin Mary". On the Feast of the Immaculate Conception, the brief Dance of the Sixteen (Spanish: Los Seises) (the actual number of choirboys dancing has been reduced to twelve) is performed by choirboys dressed in white and blue in the Cathedral of Seville. Since 1864, Mass vestments for the feast in Spain may be blue at the expressed permission with decree from the Sacred Congregation of Rites which thus became extended to the former territories of the Spanish crown and kingdom. Many other Spanish cultural customs and religious processions are associated with the feast.
On 14 May 2011, Pope Benedict XVI granted a Pontifical decree of Canonical coronation in Linares bearing the same Patronal title. Another image located in Castilleja de la Cuesta was crowned by the local townspeople in a so-called “Episcopal coronation” in 2013.
On 7 December 1650, the Irish Catholic Confederation, on the verge of its final defeat by the Cromwellian conquest of Ireland, declared the Virgin Mother of God, under the title of the Immaculate Conception, patroness of the Kingdom of Ireland and was cited six days later:
By a unanimous vote of the Supreme Assembly it was decreed that the Virgin Mother of God, under her title of her Immaculate Conception, should be solemnly and publicly proclaimed Patroness of the Kingdom of Ireland, and that as a perpetual memorial to the happy event, the feast of the Immaculate Conception should be solemnly observed in Ireland from that day forward until the end of time."
The Immaculate Conception is venerated as Patroness of the Nicaraguan people.
A letter of 1673 cites a document of 5 January 1626 according to which the statue was given by Saint Teresa of Avila to her brother, who brought it to where it now is and died there. Another document, drawn up in 1751 after a visit to the settlement of El Viejo, where the statue is kept, and citing the 1673 letter, states that the name "Nuestra Señora del Viejo" was a reference to Saint Teresa's brother, who was then an old man ("viejo" being Spanish for "old"). It describes the statue and its adornment, including a crown. A traditional story is that the statue was brought by an old hermit who, when the ship he was travelling on refused to leave the harbour, explained that the statue wished to remain there. A Carmelite report of 1786 recorded the tradition that the statue was a gift of Saint Teresa to her brother or uncle, who was governor of the locality, and that, when he attempted to take the statue with him when transferred to another governorship, storms repeatedly drove his ship back, so that he left the statue there. Another source gives the name of Saint Teresa's brother as Don Lorenzo de Cepeda and repeats the story of the storm forcing him to leave the statue in what was then called Chamulpa and is now El Viejo. The statue was ceremoniously crowned by the local townspeople in 1747.
Pope John Paul II issued the Papal bull for the Canonical coronation for the image on 28 December 1989, which was signed and executed by Cardinal Agostino Casaroli. On 7 February 1996, the same Pontiff visited the shrine on his second apostolic visit to Nicaragua. The same Pontiff raised the sanctuary of El Viejo to the status of Minor Basilica on 20 December 1995. 
On 7 October 1996, the Episcopal Conference of Nicaragua conferred the title "The National Shrine of the Immaculate Conception of El Viejo"; and on 13 May 2001, the Episcopal Bishops' Conference of Nicaragua declared the Virgin Mary under this title be the National Patroness of the country.
On 4 August 2012, Pope Benedict XVI sent the image a golden pearl rosary in recognition of the piety of the Nicaraguan people's. That same year, Nicaragua celebrated the 450th annual patronage of the Immaculate Conception with grand parades and national festivities.
A popular custom (especially among children) in Nicaragua during this time is to gather in a group and sing several Marian hymns in front of people's houses where a statue of the Immaculate Conception is enshrined. Similar to caroling songs during Christmas time, children receive special candies or sweet treats given by the household after the conclusion of singing Marian hymns.
In Leon, Nicaragua, the feast is begun by a special day of penitence conducted each December 6, when the faithful take part in publicly cleaning all the silver treasures and accessories donated to the statue. The event is also celebrated with a tradition called Gritería or "Shouting" in honor of the Virgin Mary's conception and is composed of grand parades, fireworks, candlelight processions, songs and various religious activities related to the conception of the Blessed Virgin Mary and her maternal role in Roman Catholicism. Similar practices are observed in various other Catholic countries.
By royal decree under the House of Braganza, the Immaculate Conception is the Patroness of Portugal. An image of the Immaculate Conception venerated in the Shrine of Our Lady of Conception of Villa Vicosa was donated by Saint Nuno Álvares Pereira.
On 25 March 1646, King John IV of Portugal proclaimed Our Lady of the Immaculate Conception the nation's patroness, so that 8 December is a special feast day in Portugal. Upon crowning the image since that time, the Portuguese monarchs of the House of Braganza renounced wearing a crown on their heads.
In addition, the king minted both gold and silver coins bearing his seal while on the other side bears the Immaculate Conception with the Latin phrase titled Tutelaris Regni. In 1946, at the 300th anniversary of this royal declaration, the government of Portugal also released a postal stamp commemorating its patronage featuring the image of the Virgin Mary.
The first document invoking the Marian patronage is found the king's address to the National Royal Chambers dated 30 June 1654 and was next followed again in the Royal Provision of 1646.
The statue's design is unlike most Immaculate Conception images, as the Virgin Mary carries a child Jesus rather than portrayed as being raised into Heaven. On 6 February 1818, the Order of the Immaculate Conception of Vila Viçosa was erected in the Virgin Mary's patronal honor by King John VI of Portugal. The feast marks one of the four national holidays in the Portugal.
Sanctis Congregationis Generalis de Propaganda Fide Quo Deipara Virgo, Sine Labe Originali Concepta, Septentrionalis Americae Foederatae Provincialum Patrona Instituitur