Steven Emerson (born June 6, 1954), also known as Steve Emerson, is an American investigative journalist, author, pundit, and expert on terrorism specializing in national security, terrorism, Islamic extremism, radical Islam, and jihadist networks. He focuses particularly on tracking Islamist networks and radicalization within the United States. Emerson holds a B.A. in Political Science from Brown University (1976) and has taught at Boston University and the U.S. Naval Academy.

He is the founder and executive director of The Investigative Project on Terrorism (IPT), a nonprofit research group and data center established in 1995 that tracks Islamist groups, terrorism financing, and national security threats. Emerson oversees a database of over 100,000 documents related to terrorism investigations and is a frequent media commentator, including appearances on Fox News. He has collaborated with researchers such as Jacobs and organizations like The David Project, conducting research on individuals linked with Islamist organizations such as the Islamic Society of Boston.

Emerson gained prominence with his 1988 book "The American House of Saud" and his 1994 PBS documentary "Terrorists Among Us: Jihad in America," which won him a George Polk Award for Television Reporting. He authored other books including "American Jihad: The Terrorists Among Us" (2002) and contributed to major publications such as The New York Times, The Wall Street Journal, and CNN. His investigative work has tracked funding and operations of groups such as Hamas and Hezbollah affiliates in the U.S., notably contributing to the conviction of the Holy Land Foundation for terrorism financing. He has also testified before Congress on terrorism-related issues.

Emerson's career has influenced U.S. counterterrorism policy and prosecutions related to terrorism financing. Operating from IPT’s base in Washington, D.C., he continues shaping narratives on radicalization and counterterrorism while exposing Islamist networks in the United States.

His work has been controversial, drawing criticism for alleged bias, inaccuracies, and Islamophobia. Notable incidents include a 1995 error misidentifying a YMCA as a "Muslim terrorist training camp," a 2015 false claim about the Boston Marathon bombers' uncle, and a 2015 Fox News statement about a "Muslim ghetto" in Birmingham, UK, which he later retracted following backlash for promoting Islamophobia. Organizations such as CAIR have accused him of anti-Muslim bias and selective reporting, resulting in legal disputes including defamation suits.

Emerson maintains strong ties to conservative and pro-Israel circles, receiving financial support from donors such as Nina Rosenwald and Roger Hertog, and holds professional connections with figures like Daniel Pipes.