南海泡沫事件（英语：South Sea Bubble）是英国在1720年春天到秋天之间发生的一次经济泡沫，它与同年的密西西比泡沫事件及1637年的郁金香狂热并称欧洲早期的三大经济泡沫。「经济泡沫」一语即源于南海泡沫事件。

事件起因源于南海公司（South Sea Company），南海公司在1711年西班牙王位继承战争仍然进行时创立，它表面上是一间专营英国与南美洲等地贸易的特许公司，但实际上是一所协助政府融资的私人机构，分担政府因战争而欠下的债务。南海公司在夸大业务前景及进行舞弊的情况下被外界看好，到1720年，南海公司更透过贿赂政府，向国会推出以南海股票换取国债的计划，促使南海公司股票大受追捧，股价由原本1720年年初约120英镑急升至同年7月的1,000镑以上，全民疯狂炒股。

The South Sea Company (officially The Governor and Company of the merchants of Great Britain, trading to the South Seas and other parts of America, and for the encouragement of fishing) was a British joint-stock company founded in 1711, created as a public-private partnership to consolidate and reduce the cost of national debt. The company was also granted a monopoly to trade with South America, hence its name. At the time it was created, Britain was involved in the War of the Spanish Succession and Spain controlled South America. There was no realistic prospect that trade would take place and the company never realised any significant profit from its monopoly. Company stock rose greatly in value as it expanded its operations dealing in government debt, peaking in 1720 before collapsing to little above its original flotation price; this became known as the South Sea Bubble.