Lithuania is one of the three Baltic States (Lithuania, Latvia & Estonia), located in Northern Europe, along the southeastern shore of the Baltic Sea. Lithuania shares borders with Latvia to the north with a border length of 453 km (282 miles), Belarus to the southeast with a border length of 502 km (312 miles), Poland to the southwest with a border length of 91 km (57 miles) and the Russian Federation to the west (the Russian territory adjacent to Lithuania is Kaliningrad Oblast, which is the northern part of the former German East Prussia, including the city of Kaliningrad) with a border length of 227 km (141 miles). Lithuania is about 65,200 square kilometers (26,080 square miles) in area with a coastline of about 108 kilometers (67 miles). In comparison, Lithuania is slightly larger than West Virginia. The country is divided into four regions: Aukštaitija (the highlands in the northeast and central portion of the country), Žemaitija (the lowlands in the west), Dzūkija (the southeast) and Suvalkija (the southwest).

Lithuania is glacially flat, except for the hills (of no more than 300 meters) in the western and eastern highlands. The terrain is marked by numerous small lakes, swamps and fertile soil and a mixed forest zone that covers about 30% of the country. Lithuania's principal natural source is agricultural land. The three major rivers in Lithuania are Nemunas (937 km total / 475 km in country), Neris (510 km total / 235 km in country) and Venta (346 km total / 161 km in country), and others include Šešupė, Šventoji, Nevėžis, Merkys and Minija. According to some geographers, Lithuania's capital "Vilnius" lies at the geographical center of Europe, in the southwestern part of the country.

There are 103 cities in Lithuania, listed by the size of its population: Vilnius, Kaunas, Klaipėda, Šiauliai, Panevėžys, Alytus, Marijampolė, Mažeikiai, Jonava, Utena, Kėdainiai, Telšiai, Visaginas, Tauragė, Ukmergė, Plungė, Šilutė, Kretinga, Radviliškis, Druskininkai, Palanga, Rokiškis, Biržai, Gargždai, Kuršėnai, Elektrėnai, Jurbarkas, Garliava, Vilkaviškis, Raseiniai, Naujoji Akmenė, Anykščiai, Lentvaris, Grigiškės, Prienai, Joniškis, Kelmė, Varėna, Kaišiadorys, Pasvalys, Kupiškis, Zarasai, Skuodas, Kazlų Rūda, Širvintos, Molėtai, Švenčionėliai, Šakiai, Šalčininkai, Ignalina, Kybartai, Pabradė, Šilalė, Pakruojis, Nemenčinė, Trakai, Švenčionys, Vievis, Lazdijai, Kalvarija, Rietavas, Ziežmariai, Eišiškės, Ariogala, Venta, Šeduva, Birštonas, Akmenė, Tytuvėnai, Rudiškės, Pagėgiai, Neringa, Vilkija, Žagarė, Viekšniai, Skaudvilė, Ežerėlis, Gelgaudiškis, Kudirkos Naumiestis, Simnas, Salantai, Linkuva, Veisiejai, Ramygala, Priekulė, Joniškėlis, Jieznas, Daugai, Obeliai, Varniai, Virbalis, Vabalninkas, Seda, Subačius, Baltoji Vokė, Dukštas, Pandėlys, Dusetos, Užventis, Kavarskas, Smalininkai, Troškunai and Panemunė.

Lithuania's climate, which ranges between maritime and continental with wet, moderate winters and summers, is relatively mild. Average temperatures are -5ºC (23ºF) in January and 17ºC (62.6ºF) in July. A frequent average summer temperature is 20ºC (68ºF) during the day and 14ºC (57.2ºF) at night, although extreme temperatures can reach all the way up to 37.5ºC (99.5ºF) in the summer and all the way down to -42.9ºC (-45.2ºF) in the winter. The level of precipitation varies considerably from region to region: in the far west, the average annual precipitation is 28-33 inches, while in the central plain, it is about 24 inches.