Johannes Hage (1842 – 1923) was a Danish businessman who became a philanthropist and later founder of the Nivaagaard museum.

He was the son of a brickworks director whose estate and complex at Nivaagaard he inherited in 1872.

[1] Under his direction the company prospered by supplying bricks to building projects in Copenhagen.

He opened it to the public and in 1908 he made up a will in which he bequeathed the entire collection to the state, along with the museum building and a capital of 60,000 Danish marks for maintenance.

In 1913 the later director and curator of the National Museum, Karl Madsen, wrote a catalog of his collection.