The Nevėžis (/nɪˈvɛʒɪs, nɛ-/; Lithuanian: [nʲɛˈvʲěːʑɪs] ⓘ) is the sixth longest river in Lithuania and one of the main tributaries of the Nemunas.

[2] The Soviet-Belarusian geographer Vadim Zhuchkevich [ru] suggested that the name Nevėžis could be derived from a Finnish word nevo meaning 'swamp'.

The river gave name to many things including Panevėžys, the fifth-largest city in Lithuania.

During the Middle Ages, the river was considered to be a natural border between two regions of Lithuania: Samogitia and Aukštaitija.

The largest are: In 1992, the Krekenava Regional Park was established in order to preserve the Middle Nevėžis ecosystem and natural surroundings.

In more recent years, a number of grass carp was introduced to the river for aquatic weed control.

The Nevėžis, due to its low level of water, slow current, and influx of the run-off of fertilizers from agriculture, was becoming more and more overgrown with weeds.

The land between the rivers was low and there was a small Sanžilė rivulet which could serve as the basis for the new canal.