The Patriottentijd (Dutch pronunciation: [pɑtriˈjɔtə(n)ˌtɛit] ^ⓘ; lit. 'Time of the Patriots') was a period of political instability in the Dutch Republic between approximately 1780 and 1787. Its name derives from the Patriots (Patriotten) faction who opposed the rule of the stadtholder, William V, Prince of Orange, and his supporters who were known as Orangists (Orangisten). In 1781 one of the leaders of the Patriots, Joan Derk van der Capellen tot den Pol, influenced by the reformer Richard Price and the dissenter Joseph Priestley, anonymously published a pamphlet, entitled Aan het Volk van Nederland ("To the People of the Netherlands"), in which he advocated, like Andrew Fletcher, the formation of civic militias on the Scottish, Swiss and American model to help restore the republican constitution.

Such militias were subsequently organised in many localities and formed, together with Patriot political clubs, the core of the Patriot movement. From 1785 on, the Patriots managed to gain power in a number of Dutch cities, where they replaced the old system of co-option of regenten with a system of democratically elected representatives. This enabled them to replace the representatives of these cities in the States of several provinces, gaining Patriot majorities in the States of Holland, Groningen and Utrecht, and frequently also in the States General. This helped to emasculate the stadtholder's power as he was deprived of his command over a large part of the Dutch States Army. A low-key civil war ensued that resulted in a military stalemate, until in September–October 1787 the Patriots were defeated by a Prussian army and many were forced into exile.

The term Patriot (from Greek πατριώτης, "fellow countryman") had previously been used mid 17th century by Andries Bicker and the Loevestein faction, but when French troops invaded the Republic in 1747, "Patriots" demanded the return of the Orange stadtholderate, which ended the Second Stadtholderless Period. From 1756 onward, however, Dutch States Party regenten once again began styling themselves "Patriots". The Orangist party did try to reappropriate the term, but it was forced on the defensive, which became apparent when it renamed one of its weekly magazines to De Ouderwetse Nederlandsche Patriot ("The Old-Fashioned Dutch Patriot"). Patriotism and anti-Orangism had become synonymous.

The Patriots can be divided into two separate groups: aristocrats and democrats. The aristocratic Patriots (also called oudpatriotten or "Old Patriots"), initially the strongest, can be viewed as oppositional regenten, who either sought to enter the factions in power, or tried to realise the so-called "Loevesteinian" ideal of a republic without Orange; they came from the existing Dutch States Party. The democratic Patriots emerged later, and consisted mainly of non-regent members of the bourgeoisie, who strove to democratise the Republic.

Finally, the term Patriottentijd for the historical era is a historiographical invention of 19th-century Dutch historians, comparable to the terms "First Stadtholderless Period", "Second Stadtholderless Period", and "Fransche Tijd (French Era)" (for the era of the Batavian Republic, the Kingdom of Holland and the French First Empire, 1795–1813). Herman Theodoor Colenbrander for instance, used the term as the title of one of his main works: De patriottentijd: hoofdzakelijk naar buitenlandsche bescheiden (The Hague, 1897). The term was often used in a pejorative fashion, but lately has acquired a more positive connotation.

After the halcyon days of the Dutch Golden Age of the first two-thirds of the 17th century, the Dutch economy entered a period of stagnation and relative decline. The absolute size of Dutch GNP remained constant, but the economy was overtaken by that of other European countries in the course of the 18th century. Besides, in a number of economic sectors, such as the fisheries and most industries that had sprung up in the early 17th century, an absolute decline occurred. The country's deindustrialization resulted in de-urbanization as artisans that had worked in the disappearing industries had to move to areas where work was still to be found. The shrinking industrial base was also concentrating in particular areas, to the detriment of other areas where certain industries (shipbuilding, textiles) had formerly been prominent. Remarkably for an era of rapid population growth in other European countries, the size of the Dutch population remained constant during the 18th century at around 1.9 million people, which (in view of the constant absolute size of the economy) resulted in a constant per capita income. But this was somewhat misleading as economic inequality markedly increased during the 18th century: the economy became dominated by a small group of very rich rentiers, and the economy shifted to what we would now call a service economy, in which the commercial sector (always strong in the Netherlands) and the banking sector dominated. These shifts had a devastating effect for the people who experienced downward social mobility and ended up in the lower strata of Dutch society. But even those that were not affected by such downward mobility, and remained in the upper and middle classes, were affected by this perceived economic decline.

The economic decline worked through in the political sphere as after the Peace of Utrecht of 1713 the government of the Dutch Republic felt constrained to enter upon a policy of austerity as a consequence of the dire state of the Dutch public finances. Both the (mercenary) Dutch States Army and the Dutch navy suffered a large shrinkage in the following period, and consequently the Republic had to give up the pretense of being a European great power, in the military sense, with the diplomatic consequences that entailed. It became clear that the Republic had become a pawn in European power politics, depending on the good will of other countries such as France, Prussia and Great Britain. This decline in international diplomatic standing also contributed to the malaise that resulted from the perceived decline.

The disaffection with the perceived state of the economy and diplomatic decline was paired with a growing disaffection with the political system of the Dutch Republic among middle-class Dutchmen. The Dutch "constitution" defined the Dutch Republic as a confederation of sovereign provinces with a republican character. Formally, power was supposed to flow upward, from the local governments (governments of select cities that possessed City Rights, and the aristocracy in rural areas) toward the provincial States, and eventually the States-General. Those local governments, however, though ostensibly representing "The People" according to the prevailing ideology, had in fact evolved into oligarchies dominated by a few families that in the cities at least were not formally part of the nobility, but were considered "patrician" in the classical sense. The members of the regenten class co-opted each other in the city council, which elected the magistrates and sent delegates to the regional and national States. This situation had come about gradually, as in medieval times corporate institutions, like the guilds and schutterijen had sometimes had at least nominating powers to the vroedschappen, bestowing a certain amount of political power on members of the middle class (though calling this "democracy" would be an exaggeration).