Yelp Inc. is an American company that develops the Yelp.com website and the Yelp mobile app, which publish crowd-sourced reviews about businesses. It also operates Yelp Guest Manager, a table reservation service. It is headquartered in San Francisco, California.

Yelp was founded in 2004 by former PayPal employees Russel Simmons and Jeremy Stoppelman. Yelp grew in usage and raised several rounds of funding in the following years. By 2010, it had $30 million in revenue, and the website had published about 4.5 million crowd-sourced reviews. From 2009 to 2012, Yelp expanded throughout Europe and Asia. In 2009, it entered unsuccessful negotiations to be acquired by Google. Yelp became a public company via an initial public offering in March 2012 and became profitable for the first time two years later.

As of December 31, 2021, approximately 244.4 million reviews were available on its business listing pages. In 2021, the company had 46 million unique visitors to its desktop webpages and 56.7 million unique visitors to its mobile sites. Over 50% of the company's audience has an annual household income of more than $100,000.

The company has been accused of using unfair practices to raise revenue from the businesses that are reviewed on its site – e.g., by presenting more negative review information for companies that do not purchase its advertising services or by prominently featuring advertisements of the competitors of such non-paying companies or conversely by excluding negative reviews from companies' overall rating on the basis that the reviews "are not currently recommended". There have also been complaints of aggressive and misleading tactics by some of its advertising sales representatives. The company's review system's reliability has also been affected by the submission of fake reviews by external users, such as false positive reviews submitted by a company to promote its own business or false negative reviews submitted about competing businesses – a practice sometimes known as "astroturfing", which the company has tried to combat in various ways.