The Arnolfini Portrait (or The Arnolfini Wedding, The Arnolfini Marriage, the Portrait of Giovanni Arnolfini and his Wife, or other titles) is an oil painting on oak panel by the Early Netherlandish painter Jan van Eyck, dated 1434 and now in the National Gallery, London. It is a full-length double portrait, believed to depict the Italian merchant Giovanni di Nicolao Arnolfini and his wife, presumably in their residence at the Flemish city of Bruges.

It is considered one of the most original and complex paintings in Western art, because of its beauty, complex iconography, geometric orthogonal perspective, and expansion of the picture space with the use of a mirror. According to Ernst Gombrich "in its own way it was as new and revolutionary as Donatello's or Masaccio's work in Italy. A simple corner of the real world had suddenly been fixed on to a panel as if by magic... For the first time in history the artist became the perfect eye-witness in the truest sense of the term". The portrait has been considered by Erwin Panofsky and some other art historians as a unique form of marriage contract, recorded as a painting. Signed and dated by van Eyck in 1434, it is, with the Ghent Altarpiece by the same artist and his brother Hubert, the oldest very famous panel painting to have been executed in oils rather than in tempera. The painting was bought by the National Gallery in London in 1842.

Van Eyck used the technique of applying several layers of thin translucent glazes to create a painting with an intensity of both tone and colour.

Jan van Eyck ( van EYEK; Dutch: [ˈjɑɱ vɑn ˈɛik]; c. before 1390 – 9 July 1441) was a Flemish painter active in Bruges who was one of the early innovators of what became known as Early Netherlandish painting, and one of the most significant representatives of Early Northern Renaissance art. According to Vasari and other art historians including Ernst Gombrich, he invented oil painting, though most now regard that claim as an oversimplification.

The surviving records indicate that he was born around 1380 or 1390, in Maaseik (then Maaseyck, hence his name), Limburg, which is located in present-day Belgium. He took employment in The Hague around 1422, when he was already a master painter with workshop assistants, and was employed as painter and valet de chambre to John III the Pitiless, ruler of the counties of Holland and Hainaut. After John's death in 1425, he was later appointed as court painter to Philip the Good, Duke of Burgundy, and worked in Lille before moving to Bruges in 1429, where he lived until his death. He was highly regarded by Philip, and undertook a number of diplomatic visits abroad, including to Lisbon in 1428 to explore the possibility of a marriage contract between the duke and Isabella of Portugal.

About 20 surviving paintings are confidently attributed to him, as well as the Ghent Altarpiece and the illuminated miniatures of the Turin-Milan Hours, all dated between 1432 and 1439. Ten are dated and signed with a variation of his motto ALS ICH KAN (As I (Eyck) can), a pun on his name, which he typically painted in Greek characters.

Van Eyck painted both secular and religious subject matter, including altarpieces, single-panel religious figures and commissioned portraits. His work includes single panels, diptychs, triptychs, and polyptych panels.