Södertälje is a city located in Stockholm County, Sweden. It serves as the seat of the Södertälje Municipality and is an integral part of the Greater Stockholm Metropolitan Area. As of 2020, the city had a population of 73,872 inhabitants.
The city is situated at the confluence of Lake Mälaren and the Baltic Sea, connected by a lock in the Södertälje Canal. Since the year 2000, it has held the distinction of being the largest city located entirely within the province of Södermanland.