Dutch biblical, genre, and portrait painter, a gifted and favourite pupil of Rembrandt (1635–40), to whom he remained a close friend. His usual style is based so closely on that of his master that many of his pictures have passed as works of Rembrandt himself. Eeckhout was one of the most successful of this school in adopting the broader and bolder technique of Rembrandt's mature style, though he seldom approached the master in humanity or depth of feeling.

In surprising contrast to his normal Rembrandtesque style are a number of highly finished genre subjects—guardroom scenes, backgammon players, and so on. An example of the early style, once thought to be by Rembrandt, is the “Christ Raising the Daughter of Jairus” in the Staatliche Museen Preussischer Kulturbesitz, Berlin. A good example of genre in the manner of Terborch is “The Music Lesson” of 1655, in the Statens Museum for Kunst, Copenhagen. The National Gallery in London has a fine group portrait of “Four Officers of the Amsterdam Coopers' and Wine-Rackers' Guild” dated 1657.