Sea Sonic Electronics Co., Ltd. (Chinese: 海韻電子工業股份有限公司; pinyin: hǎiyùn diànzǐ gōngyè gǔfèn yǒuxiàngōngsī), stylized as Seasonic, is a Taiwanese power supply and computer PSU manufacturer and retailer, formerly limited to trading hardware OEM for other companies.

[1] They first started making power supplies for the PC industry in the 1981.

All of their PSUs are 80 Plus-certified.

In 2002, Sea Sonic established a wholly owned subsidiary in California to sell products in the US retail market and to provide technical support.