Sina (NASDAQ: Sina), also known as Sina Corporation, is an online media company that serves the Chinese and global Chinese communities. It was founded in December 1998 by Wang Zhidong and is currently chaired by Cao Guowei. Sina serves the Greater China region and overseas Chinese communities, and has multiple regional websites.

Sina helps users obtain professional media and user generated multimedia content (UGC) through its portal website Sina.com, Sina Mobile, and social media Weibo, and share their interests with friends through computers and mobile devices.

In November 2012, Sina's registered users exceeded 400 million. As of the fourth quarter ending December 31, 2016, revenue was $313 million, a year-on-year increase of 22%; Net profit was 19.9 million US dollars, a year-on-year increase of 37%; Diluted earnings per share were $0.27, a year-on-year increase of 29%; For the year ended December 31, 2016, revenue was $1.0309 billion, a year-on-year increase of 17%; Net profit was $225.1 million, with diluted earnings per share of $3.01.

On April 13, 2000, Sina successfully went public on NASDAQ. On August 3, 2017, the 2017 "Top 100 Internet Enterprises in China" list was released, and Sina ranked sixth. On September 1, 2019, the 2019 Top 500 Chinese Service Enterprises list was released in Jinan, with Sina Corporation ranking 302nd.