The Tammy sex video scandal was an incident in Singapore involving a sex video first circulated in mid-February 2006 that turned into an Internet phenomenon. The incident began when a cheerleader and student from Nanyang Polytechnic (NYP), known only as Tammy, apparently had her mobile phone stolen by a nemesis, and a 10-minute video stored in her phone involving oral sex and intercourse with her boyfriend was uploaded on the Internet.

The video was initially spread obscurely via instant messaging, email and blogs, but eventually made it to the front pages of national newspapers. Shortly after, the video gained international notoriety as many people curiously began searching for it online under the keyword Tammy Nyp, causing the scandal to make it to the first five places in Technorati's top search terms for almost two weeks. Bloggers who mentioned the scandal found themselves experiencing a spike in their visitor traffic. The video was reportedly sold on DVDs at Penang, Malaysia, and made it as far as New York City. A domain on the scandal's top search term was also squatted, and other merchandise such as T-shirts was sold online.

Questions on morality have been raised and debated after the scandal broke. Critics blamed the girl for shooting the video in the first place, while others pointed the finger at the person who uploaded the video. Her boyfriend, on the other hand, has escaped the same level of the criticism thrust upon Tammy, prompting comments questioning some critics' bias. The girl, when interviewed, claimed that she had no intention for fame or being a porn star, and has since undergone counselling.