Groenlo (Dutch pronunciation: [ˈɣrunloː] ⓘ) is a city in the municipality of Oost Gelre, situated in the eastern part of the Netherlands, on the German border, within a region in the province of Gelderland called the Achterhoek (literally: "back corner").

Today, Groenlo is known primarily for its beer brewery Grolsch (literal meaning: "from Grol"), which was in business since 1615, but has been closed in 2004 when it moved to Boekelo.

The city still has a defensively shaped Gracht (canal) and (the remains of) bulwarks stemming from this era.

Tourism is of major importance to Groenlo, with over 3500 tourists spending the night locally at given times.

Groenlo has been under Spanish control for a considerable time during its violent history, which has left its marks.

This has resulted in several Catholic traditions being celebrated locally, such as Carnaval and "Kermis", as well as a relatively large number of licensed establishment and festivities.