The RMS Oceanic(I) was the White Star Line's first liner and an important turning point in passenger liner design.

She was built by Harland and Wolff at their Belfast yards. She was launched on 27 August 1870 and arrived in Liverpool for her maiden voyage on 26 February 1871. She was 470 ft 4 inches (143.4 m) long, 40 ft 10 inches (12.4 m) in width and had a gross tonnage of 3,707 tons (10,500 m³). Powered by a combination of steam and sail, she was designed to achieve a speed of 14.5 knots (27 km/h). Twelve boilers generating steam at 65 pounds-force per square inch (450 kPa), powered a single four cylinder compound engine, 2 x 78 inches (1.98 m) and 2 x 41 inches (1.04 m), with a stroke of 60 inches (1.52 m). A single funnel exhausted smoke and four masts carried sail. The hull was constructed of iron and divided into 11 watertight compartments. Oceanic could carry 166 first class and 1000 third class passengers. She had a crew of 143.

Oceanic left for her maiden voyage from Liverpool on the 2 March 1871 carrying only 64 passengers. Not long after departing, she had to return because of overheated bearings. Voyage was restarted on 16 March. From that point onward, the Oceanic was a success for White Star.

Innovative features included positioning the first class passenger cabins amidships, away from the vibration of engines and with the least ocean movement. Third class passengers were placed at the bow and stern of the ship. All first class could be seated at once in the first class dining saloon amidships. Portholes in the ship were much larger than on contemporary liners providing more light. Running water was available for most if not all the first class cabins. There were also electric bells to summon a steward.

Three other sister ships were constructed in rapid succession: the Atlantic, Baltic, and Republic. All were of the same approximate dimensions with differences in tonnages.

Oceanic continued sailing with the White Star line on the Liverpool to New route until 11 March 1875, when she was leased to another company. She was scrapped in 1895.