Rijswijk (Dutch: [ˈrɛisʋɛik] ⓘ), formerly known as Ryswick (/ˈrɪzwɪk/ RIZ-wik) in English, is a town and municipality in the western Netherlands, in the province of South Holland.

The village of Rijswijk formed in the 13th century, and its history was dominated by the presence of mansions and estates of the nobility and affluent.

Until 1900 Rijswijk remained a relative small community but it became urbanized during the 20th century when it expanded rapidly.

During the years its built-up area has grown to the point where it has effectively merged with The Hague, even though it is still a separate municipality.

Istana Negara, one of the six presidential palaces of Indonesia, in the Jakarta neighbourhood of Harmoni (formerly Rijswijk-Molenvliet), was called Paleis te Rijswijk during Dutch colonial times.