Roller chain or bush roller chain is the kind of chain drive mostly used for transmitting of mechanical power on many types of domestic, commercial and agricultural machinery, including conveyors, wire- and tube-drawing machines, printing presses, vehicles, motorcycles, and bicycles. It consists of a series of short cylindrical rollers held jointly by aspect links. It is powered by a toothed wheel called a sprocket. It is a simple, reliable, and efficient[1] means of power transmission.

Though Hans Renold is Stainless Steel Chain credited with inventing the roller chain in 1880, sketches by Leonardo da Vinci in the 16th century show a chain with a roller bearing.