Place Guillaume II is a town square in Luxembourg City, in southern Luxembourg. The square lies to the west of Krautmaart and to the north of Boulevard Franklin Delano Roosevelt in the heart of Luxembourg's historic Ville Haute quarter. It is colloquially known as Knuedler, from the Luxembourgish language's word for 'knot', referring to the knot in the belt worn by Franciscan friars.
The western half of the square is dominated by Luxembourg City Hall in the southwest, whilst the equestrian statue to former Grand Duke William II, after whom the square is named, is the prominent feature of the eastern half. Much of the square is ringed with trees, narrowing the open area (particularly around the statue).
The square was originally the site of a Franciscan monastery, hence the colloquial name. However, in 1797, during the French Revolutionary Wars, the monastery was dispossessed by occupying French soldiers. In 1804, the visiting Napoleon presented Place Guillaume II to the city as a gift. In 1829, plans were put in place to build a new town hall on the square, based upon the plans of Belgian architect Justin Remont. That same year, the deconstruction of the former monastery was completed, the material from which was used in the new building.