In the West

The Catholic holiday of All Saints' Day falls on 1 November, followed by All Souls' Day on 2 November, and is a Holy Day of Obligation in the Latin Rite of the Catholic Church.

In the early days the Christians were accustomed to solemnize the anniversary of a martyr's death for Christ at the place of martyrdom. In the fourth century, neighbouring dioceses began to interchange feasts, to transfer relics, to divide them, and to join in a common feast; as is shown by the invitation of St. Basil of Caesarea (397) to the bishops of the province of Pontus. In the persecution of Diocletian the number of martyrs became so great that a separate day could not be assigned to each. But the Church, feeling that every martyr should be venerated, appointed a common day for all. The first trace of this we find in Antioch on the Sunday after Pentecost. We also find mention of a common day in a sermon of St. Ephrem the Syrian (373), and in the 74th homily of St. John Chrysostom (407). At first only martyrs and St. John the Baptist were honored by a special day. As early as 411 there is in the Chaldean Calendar a "Commemoratio Confessorum" for the Friday after Easter.

On 13 May 609 or 610, Pope Boniface IV consecrated the Pantheon at Rome to the Blessed Virgin and all the martyrs, ordering an anniversary; the feast of the dedicatio Sanctae Mariae ad Martyres has been celebrated at Rome ever since. There is evidence that from the fifth through the seventh centuries there existed in certain places and at sporadic intervals a feast date on 13 May to celebrate the holy martyrs. The origin of All Saints' Day cannot be traced with certainty, and it has been observed on various days in different places. However, there are some who maintain the belief that it has origins in the pagan observation of 13 May, the Feast of the Lemures, in which the malevolent and restless spirits of the dead were propitiated. Liturgiologists base the idea that this Lemuria festival was the origin of that of All Saints on their identical dates and on the similar theme of "all the dead".

The feast of All Saints, on its current date, is traced to the foundation by Pope Gregory III (731–741) of an oratory in St. Peter's for the relics "of the holy apostles and of all saints, martyrs and confessors, of all the just made perfect who are at rest throughout the world", with the date moved to 1 November and the 13 May feast suppressed.

This fell on the Celtic holiday of Samhain, which had a theme similar to the Roman festival of Lemuria, but which was also a harvest festival. The Irish, having celebrated Samhain in the past, did not celebrate All Hallows Day on this 1 November date, as extant historical documents attest that the celebration in Ireland took place in the spring: "...the Felire of Oengus and the Martyrology of Tallaght prove that the early medieval churches [in Ireland] celebrated the feast of All Saints on April 20."

A November festival of all the saints was already widely celebrated on 1 November in the days of Charlemagne. It was made a day of obligation throughout the Frankish empire in 835, by a decree of Louis the Pious, issued "at the instance of Pope Gregory IV and with the assent of all the bishops", which confirmed its celebration on 1 November. The octave was added by Pope Sixtus IV (1471–1484).

The festival was retained after the Reformation in the calendar of the Anglican Church and in many Lutheran churches. In the Lutheran churches, such as the Church of Sweden, it assumes a role of general commemoration of the dead. In the Swedish calendar, the observance takes place on the Saturday between 31 October and 6 November. In many Lutheran Churches, it is moved to the first Sunday of November. In the Church of England it may be celebrated either on 1 November or on the Sunday between 30 October and 5 November. It is also celebrated by other Protestants of the English tradition, such as the United Church of Canada, the Methodist churches, and the Wesleyan Church.

Protestants generally regard all true Christian believers as saints and if they observe All Saints Day at all they use it to remember all Christians both past and present. In the United Methodist Church, All Saints' Day is celebrated on the first Sunday in November. It is held, not only to remember Saints, but also to remember all those who have died who were members of the local church congregation. In some congregations, a candle is lit by the Acolyte as each person's name is called out by the clergy. Prayers and responsive readings may accompany the event. Often, the names of those who have died in the past year are affixed to a memorial plaque.

In many Lutheran churches, All Saints' Day and Reformation Day are observed concurrently on the Sunday before or after those dates, given Reformation Day is observed in Protestant Churches on 31 October. Typically, Martin Luther's "A Mighty Fortress is Our God" is sung during the service. Besides discussing Luther's role in the Protestant Reformation, some recognition of the prominent early leaders of the Reformed tradition, such as John Calvin and John Knox, occurs. The observance of Reformation Day may be immediately followed by a reading of those members of the local congregation who have died in the past year in observance of All Saints' Day. Otherwise, the recognition of deceased church members occurs at another designated portion of the service.