SCSK Corporation (株式会社SCSK, Kabushiki-gaisha Esu-Shī-Esu-Kei) is a Japanese information technology company headquartered in Tokyo, Japan, offering IT services and computer software.

In the 2000s, its real estate investment business failed, resulting in heavy losses to the company after Okawa's death in 2001.

[4][clarification needed] In April 2011, Sumitomo Corporation acquired CSK through a takeover.

SCSK Corporation's business type and scope is similar to those of Itochu Techno-Solutions, Uniadex and Mitsui Knowledge Industry, which also specialize in IT services.

The company has been listed on the Tokyo Stock Exchange since 1989, then as Sumitomo Computer Service Corporation.