The Frisian freedom (/ˈfriːʒən/; Old Frisian: Fresiska fridom; West Frisian: Fryske frijheid; Dutch: Friese vrijheid; German: Friesische Freiheit; Latin: Frisonica libertas) was the form of governance, legal system and social structure in Frisia during the Middle Ages, characterised by self-government and the absence of feudalism. Its main aspects included freedom from serfdom, feudal duties and taxation, as well as the election of judges and adjudicators.

According to medieval chronicles, exemption from feudalism was granted to the Frisians by Charlemagne, although the earliest clear evidence of the Frisian freedom has been dated to the 13th century. Throughout the Middle Ages, Frisians resisted the expansion of feudalism into their lands, fighting a series of wars against the County of Holland in order to maintain their autonomy. During this period, Frisian society was organised in a network of rural communes, people largely governed themselves through public assemblies, and elected judges established a codified legal system without any kind of central government. Frisians formed treaties with other powers to protect their freedom, which was recognised by a number of German kings during the Late Middle Ages.

Frisian freedom was brought to an end in the late-15th century, as increasing levels of class stratification in the East culminated in the establishment of the County of East Frisia, while West Frisia was brought under the rule of Saxony. Since the 16th century, the Frisian freedom has been subject to numerous reinterpretations. During the Dutch Revolt, it was used to argue for the restoration of rights lost under Habsburg rule, and Frisian freedom later inspired American and French Revolutionaries. One Frisian history book from this period contained a fictionalised portrayal of the Frisian freedom, which deeply influenced later Frisian historiography. It was later recast as a national myth by Frisian nationalism, which depicted freedom as an inherent trait of the Frisian people and portrayed a level of historical continuity that is disputed by historians.

The region of Frisia extends along the North Sea coastline, from the Zuiderzee in the west to the Weser in the east. In most of western Europe during the High Middle Ages, social organisation developed along the lines of feudalism, as nobles gained the right of sovereignty over certain territories; but Frisia notably developed along a different path. Beginning in the mid-11th century, Medieval communes spread from northern Italy across much of Europe, gathering strength in areas outside the authority of feudal lords. These communes extended personal freedoms including public participation to its populace, which cultivated within them an antagonism towards feudalism. Within the Holy Roman Empire, some of these communes, including in Frisia, eliminated the power of local princes, establishing quasi-republican systems of government.

Frisian lands existed in a state of autonomy from at least the 11th century. Although Frisia was officially brought under the rule of the Holy Roman Empire, a de facto system of self-governance developed in the region. The Frisians disregarded the rights of local feudal lords, but still recognised the rule of the Empire, although this remained at a distance in practice.

The earliest references to a "Frisian freedom" date back to the 13th century, with the first documentary evidence of self-governance being found in c. 1220, while the encyclopedist Bartholomaeus Anglicus referred to Frisian attitudes towards liberty in c. 1240. Although medieval Frisia has been compared to the Italian city-states and Old Swiss Confederacy, due to their shared quasi-republican systems of government, Frisia was unique in its contemporary understanding of liberty as an intrinsic value.

For most of its history, Frisian self-governance was maintained in East Frisia, between the Weser and Lauwers rivers. Meanwhile, parts of West Frisia periodically fell under the feudal occupation of the County of Holland. During the Friso-Hollandic Wars, the concept of Frisian freedom was used to mobilise armed resistance to feudalisation attempts by the counts of Holland.

In contrast to developments in feudal counties, the Frisian nobility never developed feudal titles, knighthoods were never established, and the centralisation of polities into states was a slow-moving process. Rural communes became the dominant institutional form in Frisia, with higher-level subdivisions coalescing into self-governing districts, known as communitates terrae (West Frisian: Steatsmienskippen; German: Landesgemeinden). Frisians largely governed themselves through community assemblies, also known as things.