SS Sirius was a wooden-hulled sidewheel steamship built in 1837 by Robert Menzies & Sons of Leith, Scotland for the London-Cork route operated by the Saint George Steam Packet Company.

The ship could carry a maximum of 450 long tons (460 t) of coal, enough to steam 2,897 nautical miles (5,365 km; 3,334 mi) at an average speed of 6.7 knots (12.4 km/h; 7.7 mph).

[6] Sirius was one of the first steamships built with a condenser that enabled her to use fresh water, avoiding the need to periodically shut down her boilers at sea for cleaning.

[3] Overloaded with coal and with 45 passengers,[1] Sirius left Cork, Ireland on 4 April and arrived in New York after a voyage of 18 days, 4 hours and 22 minutes (8.03) knots.

[8] When coal ran low, the crew were alleged by the newspapers to have been forced to burn cabin furniture, spare yards and one mast, inspiring the similar sequence in Jules Verne's Around the World in Eighty Days.

[3] Because Sirius was clearly too small for the Cork-New York crossing, she completed only one additional round trip before she was returned to her owners and, after a voyage to Saint Petersburg, resumed her regular St George company service, though on the Cork-Glasgow route.

On 16 January, on a voyage to Cork from Glasgow via Dublin with cargo and passengers, she struck rocks in dense fog in Ballycotton Bay, Ireland.