Vilnius is the capital of and largest city in Lithuania, and the second-most populous city in the Baltic states. As of January 2024, Vilnius' estimat…Vilnius is the capital of and largest city in Lithuania, and the second-most populous city in the Baltic states. As of January 2024, Vilnius' estimated population was 602,430, and the Vilnius urban area which extends beyond the city limits has an estimated population of 708,627.