Eskilstuna is a city and the seat of Eskilstuna Municipality, Södermanland County, Sweden. The city of Eskilstuna had 69,948 inhabitants in 2020, with a total population of 107,806 inhabitants in Eskilstuna municipality 2023. Eskilstuna has a large Sweden Finn population. The town is located on the River Eskilstunaån, which connects Lake Hjälmaren and Lake Mälaren.

Eskilstuna Municipality is a municipality in Södermanland County in southeast Sweden, between Lake Mälaren and Lake Hjälmaren. The seat of the municipality is in the city of Eskilstuna.