The name of the town comes from two words; 'Möln', which is a short form for Möllor, an old word for mills, and the word 'dal', which is the Swedish word for valley. Mölndal is thus the Valley of Mills. The high, narrow waterfalls in Kvarnbyn provided the necessary power for all the watermills, which together with the windmills on the hills gave birth to the industrialisation of Mölndal. The municipality has a cultural and industrial heritage rooted in farming, gardening, milling and paper manufacturing. Paper manufacturing started in 1653 and continued at the very same location until 2006.

Today, Mölndal is mostly known for its high concentration of companies in the science and technology sector. AstraZeneca has one of its global research centres here, with around 3,100 employees and still growing. Several other companies specialising in pharmaceuticals, biomedicine and biotechnology are also located here. Mölndal is also famous for its harness racing at Åby and the Hills Golf Club, not to mention Gunnebo House and Gardens which in the past has played host to US president George W Bush.