小立陶宛（立陶宛语：Mažoji Lietuva；德语：Kleinlitauen；波兰语：Litwa Mniejsza；俄语：Máлая Литвá），又称普鲁士立陶宛（立陶宛语：Prūsų Lietuva；德语：Preußisch-Litauen；波兰语：Litwa Pruska）是立陶宛的五个历史和文化区域之一，在历史上曾属于普鲁士，是东普鲁士的一部分。在13世纪时期，条顿骑士团入侵这里，使得德语人口开始在这里居住。此后在很长的一段时间内，这里都属于普鲁士统治。一战之后，除了克莱佩达地区之外，小立陶宛被立陶宛吞并。战后，小立陶宛又成为苏联的一部分。现在小立陶宛的大部分地区属俄罗斯的加里宁格勒州，小部分地区属于立陶宛和波兰。

Lithuania Minor (Lithuanian:Mažoji Lietuva; German:Kleinlitauen; Polish:Litwa Mniejsza; Russian:Máлая Литвá) or Prussian Lithuania (Lithuanian:Prūsų Lietuva; German:Preußisch-Litauen, Polish:Litwa Pruska) is a historical ethnographic region of Prussia, later East Prussia in Germany, where Prussian Lithuanians or Lietuvininkai lived. Lithuania Minor enclosed the northern part of this province and got its name due to the territory's substantial Lithuanian-speaking population. Prior to the invasion of the Teutonic Knights in the 13th century, the main part of the territory later known as Lithuania Minor was inhabited by the tribes of Skalvians and Nadruvians. The land became depopulated to some extent during the warfare between Lithuania and the Order. The war ended with the Treaty of Melno and the land was resettled by Lithuanian newcomers, returning refugees, and the remaining indigenous Baltic peoples; the term Lithuania Minor appeared for the first time between 1517 and 1526. With the exception of the Klaipėda Region, which became a mandated territory of the League of Nations in 1920 by the Treaty of Versailles and was annexed to Lithuania from 1923 to 1939, the area was part of Prussia until 1945. Today a small portion of Lithuania Minor is within the borders of modern Lithuania and Poland while most of the territory is part of the Kaliningrad Oblast of Russia.