Johann Wilhelm Preyer was a German still life painter of the Düsseldorf school of painting.

Born in Rheydt, Germany, Johann Wilhelm Preyer grew up in the old town area of Eschweiler. His father was a merchant. He had a sister, Louise, and a brother Gustav, who was also a painter. Both he and his brother were very small-statured, and in his youth Preyer occasionally took advantage of this by dressing as a child to play pranks.

Beginning in 1882, Preyer studied art at the Düsseldorf Art Academy with Peter von Cornelius and became a master student of Wilhelm von Schadow. He continued his studies in the Netherlands, Munich, northern Italy, and Switzerland between 1835 and 1843. He returned to Düsseldorf in 1844.

Preyer painted mainly still lifes of flowers and fruit, and is today considered one of best artists in the genre in the 19th century, known for his minute and careful detail work. He is also one of the earliest of the group now known as the Düsseldorf school of painting. Much of his work is in the United States, although there are representative works in the Berlin National Gallery and elsewhere in Germany.

Preyer was one of the founding members of the Association of Düsseldorf Artists (1844). He occasionally took private students, one of whom was the American still life painter Helen Searle.

Around 1844, Preyer married Emilie Lachenwitz, the sister of painter Siegmund Lachenwitz. They had a daughter, also named Emilie, and a son, Paul, both of whom also became painters.