The ChS3 (Russian: ЧС3) is a type of 4-axle passenger direct current (catenary voltage of 3 kV) electric locomotive, manufactured in 1961, which was used in the Soviet Union and the Russian Federation. In 1960, due to the increase in passenger trains, the Skoda factory was ordered to design and produce a more powerful locomotive type than the . The plant's management decided to base the new electric locomotives on the ChS1 class of locomotive. Therefore, the more powerful AL4846eT traction motors and traction drive were installed in the experimental ChS1 locomotive (which had the factory designation 29E0). Thus, the ChS3 design was an improved version of the ChS1.