普鲁士君主是霍亨索伦家族成员，统治普鲁士的君主，起源于1525年的普鲁士公国。普鲁士公国是由位于波罗的海东岸的十字军国家条顿骑士团国演变而成。条顿骑士团在大团长阿尔布雷希特领导下改宗路德教和实行世俗化、创建普鲁士公国。公国原先是波兰王国的附庸，因此作为条款的一部分，普鲁士公爵要向波兰国王效忠。当统治普鲁士公国的霍亨索伦家族支系于1618年绝嗣后，公国由同一家族的勃兰登堡选侯统治。虽然名义上仍是两个不同的地区，但普鲁士公国的宗主权隶属于波兰王国，勃兰登堡选侯国属于神圣罗马帝国，两块领地在历史上一起被称为勃兰登堡-普鲁士。第二次北方战争以后，一系列条约使得普鲁士公国不再是波兰的附庸，拥有完整的主权。错综复杂的局势成为普鲁士王国创建的基础条件。由于外交的缘故，普鲁士君主在1701年至1772年称为普鲁士里的国王，主要是在神圣罗马帝国内，还是勃兰登堡选侯，普鲁士里的国王头衔是为了避免违反帝国法。随着普鲁士在十八世纪日益增长的军事力量和外交行动，普鲁士成为帝国各邦中最强大的邦国。普鲁士的国王头衔在1772年开始使用直至1871年，在普法战争后，国王威廉一世加冕为德意志帝国皇帝，之后普鲁士王国成为德意志帝国的邦国，普鲁士国王兼任德意志帝国皇帝。

The monarchs of Prussia were members of the House of Hohenzollern who were the hereditary rulers of the former German state of Prussia from its founding in 1525 as the Duchy of Prussia. The Duchy had evolved out of the State of the Teutonic Order, a Roman Catholic crusader state and theocracy located along the eastern Baltic Sea coast. The Teutonic Knights were under the leadership of a Grand Master, the last of whom, Albert, converted to Protestantism and secularized the lands which became the Duchy of Prussia. The Duchy was initially a vassal of the Kingdom of Poland, as a result of the terms of the Prussian Homage whereby Albert was granted the Duchy as part of the terms of peace following the Prussian War. When the main line of Prussian Hohenzollerns died out in 1618, the Duchy passed to a different branch of the family, who also reigned as Electors of Brandenburg in the Holy Roman Empire. While still nominally two different territories, Prussia under the suzerainty of Poland and Brandenburg under the suzerainty of the Holy Roman Empire, the two states are known together historiographically as Brandenburg-Prussia. Following the Second Northern War, a series of treaties freed the Duchy of Prussia from any vassalage to any other state, making it a fully sovereign Duchy in its own right. This complex situation (where the Hohenzollern ruler of the independent Duchy of Prussia was also a subject of the Holy Roman Emperor as Elector of Brandenburg) laid the eventual groundwork for the establishment of the Kingdom of Prussia in 1701. For diplomatic reasons, the rulers of the state were known as the King in Prussia from 1701 to 1772; largely because they still owed fealty to the Emperor as Electors of Brandenburg, the "King in Prussia" title (as opposed to "King of Prussia") avoided offending the Emperor. As the Prussian State grew through several wars and diplomatic moves throughout the 18th century, it became apparent that Prussia, and not the putative Holy Roman Empire, was the most powerful German state. By 1772, the pretense was dropped and the style "King of Prussia" was adopted. Thus it remained until 1871, when in the aftermath of the Franco-Prussian War, the King of Prussia Wilhelm I was crowned German Emperor. From that point forward, though the Kingdom of Prussia retained its status as a constituent state of the German Empire, all remaining Kings of Prussia also served as German Emperor, and that title took precedence.