Proprietary colonies were a type of colony in English America which existed during the early modern period. In English overseas possessions established from the 17th century onwards, all land in the colonies belonged to the Crown, which held ultimate authority over their management. All English colonies were divided by the Crown via royal charters into one of three types of colony; proprietary colonies, charter colonies and Crown colonies. Under the proprietary system, individuals or companies (often joint-stock companies), known as proprietors, were granted commercial charters by the Crown to establish overseas colonies. These proprietors were thus granted the authority to select the governors and other officials in the colony.

This type of indirect rule eventually fell out of favour in the English colonial empire due to a variety of reasons, including the gradual sociopolitical stabilisation of England's American colonies, the easing of bureaucratic difficulties in managing the colonies and increasing economic or administrative difficulties faced by proprietors. Successive English sovereigns sought to solidify their power and authority throughout the empire, and gradually converted proprietary colonies to Crown colonies, which were administered by officials directly appointed by the Crown. By the 18th century, most former proprietary colonies had been converted into Crown colonies.

Proprietary colonies in America were governed by a lord proprietor, who, holding authority by virtue of a royal charter, usually exercised that authority almost as an independent sovereign. These colonies were distinct from Crown colonies in that they were commercial enterprises established under authority of the crown. Proprietary governors had legal responsibilities over the colony as well as responsibilities to shareholders to ensure the security of their investments.

The proprietary system was a mostly inefficient^{[definition needed]} system, in that the proprietors were, for the most part, like absentee landlords.^{[clarification needed]} Many never even visited the colonies they owned.^{[citation needed]} By the early 18th century, nearly all of the proprietary colonies had eithersurrendered their charters to the crown to become royal colonies,^{[clarification needed]} or else had significant limitations placed on them by the crown.^{[citation needed]}

The provinces of Maryland, Carolina and several other colonies in the Americas were initially established under the proprietary system.

King Charles II used the proprietary solution to reward allies and focus his own attention on Britain itself. He offered his friends colonial charters which facilitated private investment and colonial self-government. The charters made the proprietor the effective ruler, albeit one ultimately responsible to English Law and the King. Charles II gave the former Dutch colony New Netherlands to his younger brother The Duke of York, who established the Province of New York. He gave an area to William Penn who established the Province of Pennsylvania.

The British America colonies before the American Revolution consisted of 20 colonies on the continent's mainland. After the conflict, thirteen of those became states of the United States of America. By the time of the Revolution some had consolidated multiple grants, while others, such as conflicting claims to what became the state of Vermont and the western borders of numerous states, including New York and Virginia, as well as the sovereignty of what became the state of Maine in 1820, remained unresolved well after.

In medieval times, it was customary in Continental Europe for a sovereign to grant almost regal powers of government to the feudal lords of his border districts to prevent foreign invasion. Those districts or manors were often called palatinates or counties palatine because the lord wielded the power of the king in his palace. His power was regal in kind but inferior in degree to that of the king.