The South Sea Company is a British joint-stock company that trades in South America during the 18th century.

Founded in 1711, the company is granted a monopoly to trade in Spain's South American colonies as part of a treaty during the War of the Spanish Succession.

In return, the company assumes the national debt England has incurred during the war.

Speculation in the company's stock leads to a great economic bubble known as the South Sea Bubble in 1720, which causes financial ruin for many.

In spite of this,it is restructured and continues to operate for more than a century after the Bubble.

The headquarters are in Threadneedle Street.