住友电工(Sumitomo Electric Industries)创立于1897年，是世界上最著名的通信厂商之一。其光纤光缆产销量多年来一直名列世界前列，年产值约30亿美元。住友电工(Sumitomo Electric Industries)在世界各国设有200多家子公司，在中国设有近10家分支机构。

住友政友(1572-1636)和苏我里右卫门(1572-1636)於日本古都-京都创业住友事业，迄今已有400多年历史。住友电工(Sumitomo Electric Industries)拥有住友家族近 300年悠久历史的独特炼铜生产经验和技术，融合及积累尖锐技术，住友电工(Sumitomo Electric Industries)开拓多元化多样产品於附高潜质市场。不断突破技术界限。尤以光电子，新原材，电子系统及能源等领域。住友电工(Sumitomo Electric Industries)投资遍及世界各地，亚太区於1949年投资生产，出口设施开始尤其活跃。

具有400年悠久历史的住友家族的炼铜事业，奠定了住友电工(Sumitomo Electric Industries)电线电缆生产事业的基础，住友电工(Sumitomo Electric Industries)把在制造电线的过程中开发积累的技术交叉融合，开拓出多种多样的事业，向社会推出一个又一个具有独创性的新产品。这方面，住友电工(Sumitomo Electric Industries)的历史可以说就是多种经营、多元发展的历史。应用电线拨丝技术，开发出粉末冶金产品及特殊钢丝；电线被覆材料技术的开发成功，导致了橡胶产品的问世。通过进一步的综合应用在广泛事业活动中积累起来的创造性技术，又扩展到系统、光电子等划时代的新科技领域。住友电工(Sumitomo Electric Industries)将继续应用自己独特的创造性技术，在光电子、新材料、系统为代表的崭新领域攀登新高峰。

Sumitomo Electric Industries, Ltd. (SEI) (住友電気工業株式会社 Sumitomo Denki Kōgyō) is a manufacturer of electric wire and optical fiber cables. Its headquarters are in Chūō-ku, Osaka, Japan. The company's shares are listed in the first section of the Tokyo, Nagoya Stock Exchanges, and the Fukuoka Stock Exchange. In the period ending March 2013, the company reported consolidated sales of US$23 billion (2,159,942 million Japanese yen).

The company was founded in 1897 to produce copper wire for electrical uses. Sumitomo operates in five business fields: Automotive, Information & Communications, Electronics, Environment & Energy, and Industrial materials and is developing in two others: Life Sciences and Materials & Resources. It has more than 350 subsidiaries and over 200,000 employees in more than 30 countries.

Sumitomo Electric has traditionally had an intensive focus on R&D to develop new products. Its technologies have been used in major projects including traffic control in Thailand, improvement of telecom networks in Nigeria, membrane technology for waste water treatment in Korea, and bridge construction in Germany.

Sumitomo Electric's electrical wiring harness systems, which are used to send information and energy to automobiles, hold the second largest market share in the world. Sumitomo Electric also continues to be the leading manufacturer of composite semiconductors (GaAs, GaN, InP), which are widely used in semiconductor lasers, LEDs, and mobile telecommunications devices. The company is one of the top three manufacturers in the world of optical fiber.