From the 14th century, two mills and a tavern are mentioned in Reinach. In 1588 the town was granted market rights and a marketplace was built. In the 16th and 17th centuries, the canvas weaving industry spread to the village. From about 1850 to 1970 Reinach was a center of the tobacco and cigar industry. The Wynental- und Suhrentalbahn connected the municipality in 1904 to Aarau as part of the Reinach-Menziken line. In the 20th century several companies in the metals industry settled in Reinach. Merger negotiations with neighboring communities in the upper Wynental were suspended because of little financial participation by the canton. Regional cooperation may improve as part of a regional development concept.