Johan Sylvius (probably 1620 – March 1695) was a Swedish painter. He was probably born in Sweden, and possibly died at Drottningholm Palace, in Lovön parish, Stockholm county. Sylvius spent much of his youth and manhood abroad; however, little is known about his early life. He may have been of German origin, and he worked for some years (1658–85) in Rome. During his time spent in Rome, he had the opportunity to study Peter Paul Rubens and other Netherlandish masters. Thirty-five pen-and-wash drawings survive from his time spent in Italy. These were originally the property of his colleague, Nicodemus Tessin.