Serbian Christmas traditions are customs and practices of the Serbs associated with Christmas and a period encompassing it, between the third Sunday before Christmas Day and Epiphany. Serbian Christmas is celebrated on January 7. There are many, complex traditions connected with this period. They vary from place to place, and in many areas have been updated or watered down to suit modern living. The Serbian name for Christmas is Božić (, pronounced ), which is the diminutive form of the word bog ("god"), and can be translated as "young god". Christmas is celebrated for three consecutive days, starting with Christmas Day, which the Serbs call the first day of Christmas.Christmas Day does not fall on the same day for the Serbs as for Western Christians, although they celebrate it on the same date–25 December. This is because the Serbian Orthodox Church uses the Julian calendar rather than the Gregorian one used in the West. Since 1900, the Julian calendar is 13 days behind the Gregorian calendar, and will remain so until the year 2100. During this period, 25 December in the Julian calendar–Christmas Day for the Serbs–corresponds to 7 January of the following year in the Gregorian calendar. On these days, one is to greet another person by saying "Christ is Born," which should be responded to with "Truly He is Born," or in Serbian: "Hristos se rodi" (pronounced ) – "Vaistinu se rodi" (pronounced ).

Christmas Eve The Serbian name for Christmas Eve during the day is Badnji dan, which is on January 6. After sunset it becomes Badnje veče.For the pronunciation of Serbian terms, see the section "List of terms". On this day, the family makes preparations for the oncoming celebration. The dinner on this day is festive, copious and diverse in foods, although it is prepared in accordance with the rules of fasting.

Badnjak

The badnjak is an oak log or branch brought into the house and placed on the fire on the evening of Christmas Eve, much like a yule log in other European traditions. There are many regional variations surrounding the customs and practices connected with the badnjak.

Early in the morning the head of each family, usually accompanied by several male relatives, selects and fells the tree from which the log will be cut for their household. The group announces its departure by firing guns or small celebratory mortars called prangija. The Turkey oak is the most popular species of tree selected in most regions, but other oaks, or less frequently other kinds of tree, are also chosen. Generally, each household prepares one badnjak, although more are cut in some regions.

When the head of the household finds a suitable tree, he stands in front of it facing east. After throwing grain at the tree, he greets it with the words "Good morning and happy Christmas Eve to you", makes the Sign of the Cross, says a prayer, and kisses the tree. He then cuts it slantwise on its eastern side, using an axe. The tree should fall to the east, unhindered by surrounding trees. Its top is removed, leaving the badnjak of such a length that allows it to be carried on a man's shoulder, up to about long. Once in the home, each badnjak is leaned vertically against the house beside the entrance door. In some areas, the badnjak is cut into three logs.

In the evening, a man of the family brings their badnjak into the house. If there is more than one badnjak, the thickest of them is regarded as the main one, and is brought in first. Stepping across the threshold, right foot first, the man greets his gathered family with the words "Good evening and happy Christmas Eve to you." The woman of the house greets him back, saying "May God give you well-being, and may you have good luck", or "Good luck to you, and together with you for many years to come [may we be]", or similar, before throwing grain from a sieve at the man and the badnjak he carries.

Upon entering the house the man approaches the fireplace, called ognjište () – the hearth of an ognjište is similar to a campfire, in that it has no vertical surround. He lays the badnjak down on the fire and moves it a little forward, to summon prosperity for the household. Any other logs are brought in by other males and laid on the fire parallel or perpendicular to the first. The head of the household takes a jug of wine and pours some on the badnjak; in some regions, he may strew wheat grains over the logs. He then proposes a toast: "Grant, O God, that there be health and joy in this home, that our grain and grapevines yield well, that children be born healthy to us, that our property increase in the field, pen, and barn!" or similar. The head drinks a draught of wine from the jug, after which it is passed to other members of household. When the log has burnt through, some families let the fire go out, while in others the men keep watch in shifts during the night to keep the badnjak burning.

Another type of the badnjak that has developed among the Serbs has mostly replaced the traditional log, whose burning is usually unfeasible in modern homes. It is a cluster of oak twigs with their brown leaves still attached, with which the home is decorated on the Eve. This cluster is also called the badnjak, and it is usually kept in the home until next Christmas Eve. For the convenience of those living in towns and cities, such little badnjaks can be bought at marketplaces or distributed in churches. In a common arrangement, the cluster of oak twigs is bound together with twigs of European cornel and several stalks of straw.

Since the early 1990s, the Serbian Orthodox Church has, together with local communities, organized public celebrations on Christmas Eve. There are typically three elements to such celebrations: the preparation, the ritual, and the festivity. The preparation consists of cutting down the tree to be used as the badnjak, taking it to the churchyard, and preparing drinks and food for the assembled parishioners. The ritual includes Vespers, placing the badnjak on the open fire built in the churchyard, blessing or consecrating the badnjak, and an appropriate program with songs and recitals. In some parishes, the fire on which to burn the badnjak is built not in the churchyard but at some other suitable location in their town or village. The festivity consists of gathering around the fire and socializing. Each particular celebration has its own specific traits reflecting the traditions of the local community.

Christmas straw Immediately after the badnjak has been brought in, or immediately before in some places, an armful of straw is spread over the floor. The straw is usually brought in with the same greetings and throwing of grain as the badnjak. The person spreading it may imitate a hen clucking to call her chicks, "Kvo, kvo, kvo", with the family's children imitating chicks, "Piju, piju, piju", while they pick at the straw. A common custom is to scatter a handful of walnuts over the straw.

In Petar II Petrović-Njegoš's poem The Mountain Wreath, the plot of which takes place in 18th-century Montenegro, the holiday atmosphere on Christmas Eve is described through the words of Abbot Stefan, a main character of the poem:

Ватра плама боље него игда, прострта је слама испод огња, прекршћени на огњу бадњаци; пушке пучу, врте се пецива, гусле гуде, а кола пјевају, с унучађу ђедови играју, по три паса врте се у кола, све би река једногодишници; све радошћу дивном направњено, а што ми се највише допада, што свачему треба наздравити!Petrović-Njegoš, Petar II (1990). Горски вијенац [The Mountain Wreath] (6th ed.) (in Serbian). Belgrade: Srpska književna zadruga. verses 2459–69. .Vatra plama bolje nego igda, prostrta je slama ispred ognja, prekršćeni na ognju badnjaci; puške puču, vrte se peciva, gusle gude, a kola pjevaju, s unučađu đedovi igraju, po tri pasa vrte se u kola, sve bi reka jednogodišnici; sve radošću divnom naravnjeno. A što mi se najviše dopada, što svačemu treba nazdraviti!The fire's burning brighter than ever, the straw is spread in front of the fire, Christmas logs are laid on the fire crossways; the rifles crack, and roasts on spits do turn, the gusle plays, and the dancers sing, grandfathers dance with their young grandchildren, in the kolo join three generations, it seems they're almost of the same age; everything is filled with bright mirth and joy. But what I like best of all, so help me, one has to drink a toast to everything!Petrović-Njegoš, Petar II (1986). Vasa D. Mihailovich. ed. The Mountain Wreath; translated and edited by Vasa D. Mihailovich . Irvine, California: C. Schlacks, Jr. verses 859–62, 2459–69. . Retrieved 2009-09-05.

Christmas Eve Dinner Once the badnjak and straw have been taken into the house, the Christmas Eve dinner may begin. The head of household makes the Sign of the Cross, lights a candle, and censes the whole house. In some regions it is a custom that he then goes out into the yard, calls pest animals by name (e.g. wolves, foxes, and hawks) and his personal enemies, inviting them, "Come to dinner now and again in a year, God willing." This is intended to protect the household from them for a year.

Until the beginning of the 20th century in the Pirot District, southeastern Serbia, the head of household would go out to his woodpile,The woodpile and the rubbish heap, among others, are the border zones between the human and inhuman worlds in the mytho-magical world view of South Slavs. They can be used in the communication with spiritual beings and demons. See where he would invite German (pronounced ) – a male mythological being associated with bringing rain and hail. He would take with him a loaf of bread called good luck, prepared particularly for this ritual, rakia, wine, and a wax candle. At the woodpile, he would shout three times, "German, German, wherever you are, come to dinner right now, and in the summer do not let me see your eyes anywhere!" He would then light the candle, take a sip of rakia, taste some bread, drink wine, and go back into his house. Asked what happened with German, he would answer, "He came, so we dined and drank amply of rakia and wine, and then we parted." This ritual was intended to prevent summer hailstorms.

Before the table is served, it is strewn with a thin layer of straw and covered with a white cloth. The family members sit down at the table. Prior to tucking in, they all rise and a man or boy among them says a prayer, or they together sing the Troparion of the Nativity in Church Slavonic language:

Your birth, O Christ our God, dawned the light of knowledge upon the earth. For by Your birth those who adored stars were taught by a star to worship You, the Sun of Justice, and to know You, Orient from on High. O Lord, glory to You.

Christmas Eve being a fast day, the dinner is prepared in accordance with that, but it is copious and diverse in foods. Besides a round unleavened loaf of bread called badnjački kolač, and salt, which are necessary, this meal may comprise roast fish, cooked beans, sauerkraut, noodles with ground walnuts, honey, and wine. It used to be served in some villages on a sack filled with straw, with the family seated around it on the floor. In the north Dalmatian region of Bukovica, a part of food that remained after the dinner used to be put on a potsherd, and taken to the rubbish heap. Wolf was there invited for dinner, "My dear wolf, do not slaughter my sheep, here you are groats! Here you are yours, and leave mine alone!"

Following dinner, young people visit their friends, a group of whom may gather at the house of one of them. The elderly narrate stories from the olden times. Christmas songs are sung, in which Christmas is treated as a male personage. The Serbian name for Christmas is Božić, which is the diminutive form of the noun bog "god", and can be translated as "young god". An old Christmas song from the Kotor Bay has the following lyrics:

Božić zove svrh planine, one visoke: „Veselite se, Srbi braćo, vrijeme vi je!