Karl Gustaf Patrik de Laval (Swedish pronunciation: [ˈɡɵ̂sːtav dɛ laˈvalː] ⓘ; 9 May 1845 – 2 February 1913) was a Swedish engineer and inventor who made important contributions to the design of steam turbines and centrifugal separation machinery for dairy.

The turbine wheel was mounted on a long flexible shaft, its two bearings spaced far apart on either side.

Since the materials available at the time were not strong enough for the immense centrifugal forces, the output from the turbine was limited, and large scale electric steam generators were dominated by designs using the alternative compound steam turbine approach of Charles Parsons.

He developed several types, and their success established the centrifugal separator as a useful device in a variety of applications.

De Laval also made important contributions to the dairy industry, including the first centrifugal milk-cream separator and early milking machine, the first of which he patented in 1894.