Robert Stephenson and Company was a locomotive manufacturing company founded in 1823 in Forth Street, Newcastle upon Tyne in England. It was the first company in the world created specifically to build railway engines.

Famous early locomotives were Locomotion No. 1 and Rocket. By 1899, 3,000 locomotives had been built at the Forth Street site, and a new company was formed, Robert Stephenson and Company Limited, and the Darlington works was opened.

In 1937, the company merged with Hawthorn Leslie to form Robert Stephenson and Hawthorns. In 1944, they became part of English Electric.

The company was set up in 1823 in Forth Street, Newcastle upon Tyne in England by George Stephenson, his son Robert, with Edward Pease and Thomas Richardson. The manager of the works between 1824 and 1825 was James Kennedy.

The company's first engine was Locomotion No 1, which opened the Stockton and Darlington Railway, followed by three more: Hope, Black Diamond, and Diligence. Their vertical cylinders meant these locomotives rocked excessively and at the Hetton colliery railway Stephenson had introduced "steam springs" which had proved unsatisfactory. In 1828 he introduced the "Experiment" with inclined cylinders, which improved stability, and meant that it could be mounted on springs. Originally four wheeled, it was modified for six and another example, Victory, was built. Around this time, two locomotives were built for America. The first, a four coupled loco named America, was ordered by the Boston and Providence Rail Road. The second, six-coupled and named Whistler, was built for the Boston and Providence Railroad in 1833.

In 1829, the company built a new, experimental locomotive to enter in the Rainhill Trials. Rocket had two notable improvements—a multi-tube boiler and a separate firebox. Rocket won the trials and convinced the directors of the Liverpool and Manchester Railway to use steam locomotives on their railway, and to order these locomotives, Rocket's cylinders were originally angled at an angle of 45 degrees, but were later moved to be horizontal.

The Invicta was the twentieth Robert Stephenson & Co. locomotive, and was built for the Canterbury and Whitstable Railway. Its cylinders were inclined, but moved to the front end. In 1830 came the Planet class with the cylinders inside the frames, followed by the Patentee, which added a pair of trailing wheels for greater stability with a larger boiler. This 2-2-2 design became the pattern for most locomotives, by a variety of manufacturers, for many years.

The locomotive John Bull, built in 1831, was originally of the Planet type, but was later modified. It survives and is now in the Smithsonian Institution's National Museum of American History in Washington, D.C., and is claimed to be the oldest still functional self-propelled vehicle.^{[citation needed]}