A royal court, often called simply a court when the royal context is clear, is an extended royal household in a monarchy, including all those who would regularly attend on a monarch, or another central figure. Hence, the word court may also be applied to the coterie of a senior member of the nobility. Royal courts may have their seat in a designated place, several specific places, or be a mobile, itinerant court.

In the largest courts, the royal households, many thousands of individuals constituted the court. These courtiers included the monarch or noble's camarilla and retinue, household, nobility, clergy, those with court appointments, bodyguards, and may also include emissaries from other kingdoms or visitors to the court. Foreign princes and foreign nobility in exile may also seek refuge at a court.

Near Eastern and Far Eastern courts often included the harem and concubines as well as eunuchs who fulfilled a variety of functions. At times, the harem was walled off and separate from the rest of the residence of the monarch. In Asia, concubines were often a more visible part of the court. Lower ranking servants and bodyguards were not properly called courtiers, though they might be included as part of the court or royal household in the broadest definition. Entertainers and others may have been counted as part of the court.

A royal household is the highest-ranking example of patronage. A regent or viceroy may hold court during the minority or absence of the hereditary ruler, and even an elected head of state may develop a court-like entourage of unofficial, personally-chosen advisers and "companions". The French word compagnon and its English derivation "companion" literally mean a "sharer of the bread" at table, and a court is an extension of the great individual's household. Wherever members of the household and bureaucrats of the administration overlap in personnel, it is reasonable to speak of a "court", for example in Achaemenid Persia, Ming China, Norman Sicily, the papacy before 1870 (see: papal household), and the Austro-Hungarian Empire. A group of individuals dependent on the patronage of a great man, classically in ancient Rome, forms part of the system of "clientage" that is discussed under vassal.

Individual rulers differed greatly in tastes and interests, as well as in political skills and in constitutional situations. Accordingly, some founded elaborate courts based on new palaces, only to have their successors retreat to remote castles or to practical administrative centers. Personal retreats might arise far away from official court centres.

Etiquette and hierarchy flourish in highly structured court settings, and may leave conservative traces over generations. Most courts featured a strict order of precedence, often involving imperial, royal and noble ranks, orders of chivalry, and nobility. Some courts even featured court uniforms. One of the major markers of a court is ceremony. Most monarchal courts included ceremonies concerning the investiture or coronation of the monarch and audiences with the monarch. Some courts had ceremonies around the waking and the sleeping of the monarch, called a levée. Orders of chivalry as honorific orders became an important part of court culture starting in the 15th century. They were the right of the monarch, as the fount of honour, to create and grant.

The earliest developed courts were probably in the Akkadian Empire, Ancient Egypt, and Shang dynasty. However, there is evidence of courts as described in the Neo-Assyrian Empire and Zhou dynasty. Two of the earliest titles referring to the concept of a courtier were likely the ša rēsi and mazzāz pāni of the Neo-Assyrian Empire. In Ancient Egypt, there is a title translated as high steward or great overseer of the house. The royal courts influenced by the court of the Neo-Assyrian Empire such as those of the Median Empire and the Achaemenid Empire would also have identifiable developed courts with court appointments and other features associated with later courts.

The imperial court of the Achaemenid Empire at Persepolis and Pasargadae is the earliest identifiable complex court with all of the definitive features of a royal court such as a household, court appointments, courtiers, and court ceremony. Though Alexander the Great had an entourage and the rudimentary elements of a court, it was not until after he conquered Persia that he took many of the more complex Achaemenid court customs back to the Kingdom of Macedonia, developing a royal court that would later influence the courts of Hellenistic Greece and the Roman Empire.