Kėdainiai is known for its historic old town. The Great Market Square, home to one of Lithuania's three remaining town halls, is surrounded by 17th-19th century buildings. In the square, there's a monument by Algirdas Bosas honoring the Radvila family, featuring Jonušas Radvila and historical symbols. This monument reflects the Radvilas' contributions to the town, like founding a pharmacy, printing house, and lyceum.

Kėdainiai's historic buildings include Scottish houses on Radvilų Street (numbers 5 and 21). In the 17th-18th centuries, a Scottish community settled here, opening shops and contributing to the town's prosperity. Notable structures include the former mayor Jurgis Anderson's house and the Arnet House, built by a Scottish merchant between 1624-1661, one of the town's most authentic old buildings.

Kėdainiai is home to one of Lithuania's three remaining town halls (Didžioji st. 1), along with Vilnius and Kaunas. The Renaissance-style building, remodeled in 1653-1654, originally housed a prison and archives in the basement, shops on the first floor, and magistrate offices and a courtroom on the second. Today, it contains the Civil Registry Office and an art gallery.

One of the prettiest building in Kėdainiai is The Glassmakers' House (Didžioji st. 6). It's a 17th-century building in the Dutch style