The Wuyts-Van Campen Museum opened in 1892, showing 107 paintings bestowed by Jacob Wuyts and Françoise Van Campen. The museum was expanded thanks to a cousin of Wuyts, Baron Georges Caroly. He offered the city of Lier a sum of money in 1928 to pay for a third room to be added. He subsequently donated paintings, furniture and silver.
The Timmermans-Opsomer Museum was opened in 1968 in the Hof van Geetruyen residence, representing a showcase for key cultural figures from Lier, with the main focus on two leading artists, Felix Timmermans and Isidore Opsomer. Timmermans' paintings, books, archive material and a reconstruction of his office are on display, while Opsomer's works of art and part of the studio are shown. Space was also provided later for the ornamental metalworker Lodewijk Van Boeckel, the writer Anton Bergmann and the composer Renaat Veremans.
In 2014, the city of Lier decided to strike out in a new direction with its municipal museums: the two existing museums were to be replaced by a new one. The collections belonging to the Wuyts-Van Campen and Baron Caroly municipal Museum and the Timmermans-Opsomer Museum would be housed in the new Stadmuseum Lier. Together with an ever-growing heritage collection, they help to tell us more about Lier and its residents. The focus on art is being replaced by a broader approach. The museum is being developed together with the people of Lier whose personal stories will be communicated on a broad scale.