Kavarskas (pronunciation; Polish: Kowarsk), with a population of only 700, is the fourth smallest city in Lithuania. The Šventoji River flows through the town. In 1956 near Kavarskas a water lifting station was built and part of the Šventoji River's water was channeled to the Nevėžis River. Nowadays there is a water-power plant operating there.

The name of Kavarskas comes from the surname of Stanisław Kowarski, who owned the Manor of Mažyų Pienionių (manorial place name). Although there are not many place names in Lithuania that are based on the singular of the surname, there are some (Sudargas, Musteika, perhaps Birštonas). Until the 20th century the middle town was known as Kovarsk, and around 1960 started to be called Kavarskas.

The town flag or coat of arms shows a sword creating two streams of water. The coat of arms is painted on a blue field background. It shows a golden sword stabbed into a green hill and silver water springing from the hole.

A local folk tale tells a tale about the spring of mineral water in Kavarskas. There came a time when an aging chief of the army had to choose his successor. He stabbed his sword into earth down to the hilt, and said that the warrior who will succeed him will pull the sword out. Many warriors tried, but only one was able to do it. When the rightful successor took the sword out, the ground spurted with a healthful water spring. The Spring of Saint John the Baptist is located in Kavarskas.

Where the modern town is today located, in the 15th century there was the Mažieji Pienionys (Little Pienionys) estate. At the end of the 15th century, the Grand Duke of Lithuania Alexander Jagiellon transferred the estate to Stanislovas Kovarskis, the treasurer of the king. As he had no successors, the estate was inherited by his brother, Andrius Kovarskis, the canon of the Vilnius Cathedral. Thus, the name of the Little Pienionys estate was changed to Kavarskas.

In written sources, Kavarskasas was first mentioned in 1538. In that year, a church was built. In the 16th century, Kavarskas and the surrounding area belonged to nobles Astikai, later – Ogiński (Oginskiai), Tyszkiewicz (Tiškevičiai), and Siesickiai. The Svete (Shventa) river that runs near the town was used for drinking water, crops, and to power a flour mill.

The National Resurrection Cross was built in Kaltinėnai (Silalė district).

During the summer of 1941, the Jewish population was murdered in a mass execution perpetrated by Germans and Lithuanian nationalists.

An 1892 taxpayers' list shows people listed in "Kavarskas" numbered 1,505. A 1892-1894 Lithuania Revision List included 844 names. This represents approximately 55% of the town's population in 1897, when 1546 persons were counted. In 1956, Kavarskas was granted town rights. In 2021, the town had 2,361 residents.