SS Great Western was a wooden-hulled paddle-wheel steamship with four masts, the first steamship purpose-built for crossing the Atlantic, and the initial unit of the Great Western Steamship Company. Completed in 1838, she was the largest passenger ship in the world from 1837 to 1839, the year the SS British Queen went into service.
Designed by British civil engineer Isambard Kingdom Brunel, Great Western proved satisfactory in service and was the model for all successful wooden Atlantic paddle-steamers. She was capable of making record Blue Riband voyages as late as 1843. Great Western worked to New York for eight years until her owners went out of business. She was sold to the Royal Mail Steam Packet Company and was scrapped in 1856 after serving as a troopship during the Crimean War.