OKI Semiconductor was established in 1977 as a division of OKI America Co., Ltd., which is a subsidiary of OKI Electric Industries, Inc., a Japanese company headquartered in California, USA, with manufacturing facilities in Japan and Thailand. 

OKI Semiconductor designs and markets a range of high performance IC products for communications, networking, automotive, computer and consumer electronics. Leading in CMOS memory, gate array, ASIC design and manufacturing. OKI Electric employs approximately 23,000 people. The OKI family produces a range of cutting-edge microelectronics, communications, and office electronics.

OKI products include: voice recognition / speech synthesis ICs, microcontrollers and high-performance communication devices for wireless / fiber-optic communications. Oki Semiconductor's packaging technology ranks among the best in the world, offering users a variety of options.

In 2012, Japan's Oki announced recently that they have reached a basic agreement with Japan's Rohm, which will acquire 95% of Oki's semiconductor business in order to achieve the purpose of Oki's divestiture of the semiconductor business.

OKI is product portfolio consists of LCD, memory, microcontroller, optoelectronics, power supply, RF and wireless.