Tsū is an online social networking service headquartered in New York City. Its name is said to come from the appreciation of the Japanese aesthetic, although there are crucial differences between the Iki aesthetic and Tsū. The Japanese writing of Tsū is used as the smiley logo.

Tsū was created by Evacuation Complete, LLC, a Texas corporation, which was founded on February 7, 2008. Founders of Evacuation Complete are Sebastian Sobczak, Drew Ginsburg, and Thibault Boullenger. Tsū is open to new users via invite.

Like Facebook, after registering to use the site, users may create a personal profile, add other users as friends, exchange messages, post status updates and photos, and receive notifications when others update their profiles. Tsu differentiates itself from competitors by allowing its users to maintain ownership of the content they post.

The inspiration for Tsū came from the story of Ed O'Bannon, the lead plaintiff in O'Bannon v. NCAA, an antitrust class action lawsuit against the National Collegiate Athletic Association regarding the association's use of the images of former student athletes for commercial purposes.

Tsū has been compared extensively to Ello, a contemporary social network that rejects selling user data as a product; Tsu's approach is to instead embrace the user as a product, and to sell data to advertisers and share the profits with the users as compensation This approach appears to give the service some of the characteristics of aMulti Level Marketing strategy.