The Novgorod Feudal Republic (Новгородская феодальная республика / Novgorodskaya feodal'naya respublika Новгородская земьля / Novgorodskaya zemlja) was a large mediæval Russian state which stretched from the Baltic Sea to the Ural Mountains between the 12th and 15th centuries. The name "feudal republic" has been frequently used in the Soviet-era scholarship, where it was often used by Marxist scholars to place the Novgorodian Republic within the Marxist historiographic periodization (slavery - feudalism - capitalism - socialism - communism) . Many scholars today, however, question whether or not Russia ever really had feudalism as the term is used in the medieval West. The term "Feudal Republic" was never used by the Novgorodians themselves (indeed, feudalism is a seventeenth century scholarly term); rather they referred to their city-state as "His Majesty (or Sovereign) Lord Novgorod the Great" (Государь Господин Великий Новгород = Gosudar' Gospodin Velikyi Novgorod), or more often as "Lord Novgorod the Great" (Господин Великий Новгород = Gospodin Velikyi Novgorod); The entire region - the city and its vast hinterlands - was known as The Novgorodian Land.

Novgorod has traditionally been seen as largely independent of Kiev, and while the city had a more participatory government than much of the rest of Rus', and it chose its officials locally, it still was very much a part of the Russian political and cultural landscape. The Novgorod boyars began to dominate the offices of posadnik and tysyatsky, which up until about the mid-12th century had been appointed by the grand prince in Kiev. In 1136, the Novgorodians dismissed Prince Vsevolod Mstislavich and over then next century and a half were able to invite in and dismiss a number of princes, although these invitations or dismissals were often based on who the dominant prince in Rus' or Appanage Russia was at the time, and not on any independent thinking on the part of Novgorod.

Cities like Staraya Russa, Ladoga, Torzhok and Oreshek, were part of the Novgorodian Land. According to some accounts, a vicar of the archbishop ran the city of Staraya Ladoga in the thirteenth century.

The city of Pskov was initially part of the Novgorodian Land, but had de facto independence from at least the thirteenth century. Several princes such as Dovmont and Vsevolod Mstislavich reigned in Pskov without any deference to or consultation with the prince or other officials in Novgorod. Pskov's independence was acknowledged by the Treaty of Bolotovo in 1348 (see Pskov Feudal Republic). Even after this, however, the Archbishop of Novgorod headed the church in Pskov and kept the title "Archbishop of Novgorod the Great and Pskov" until 1589. In the 12th–15th century, the Novgorodian Republic expanded east and northeast. The Novgorodians explored the areas around Lake Onega, along the Northern Dvina, and coastlines of the White Sea. In the beginning of the 14th century the Novgorodians explored the Arctic Ocean, Barents Sea, Kara Sea, and the West-Siberian river Ob.

The Ugric tribes, which inhabited the Northern Urals, had to pay tribute to Novgorod the Great. The lands to the north of the city, rich with furs, sea fauna, salt etc., were of great economic importance to the Novgorodians and they fought a protracted series of wars with Moscow beginning in the late fourteenth century in order to keep these lands. Losing them meant economic and cultural decline for the city and its inhabitants. Indeed, the ultimate failure of the Novgorodians to win these wars led to the downfall of the Republic.