Robert Bruce Spencer (born February 27, 1962, in Bedford, New Hampshire) is an American author, blogger, and activist known for his anti-Islam activism and involvement in the counter-jihad movement. He is the founder and director of the Jihad Watch blog, established in 2003 under the David Horowitz Freedom Center, which monitors jihadist activities and Islamist ideology through critical articles addressing what he perceives as Islamist ideology, jihadist threats, and the dangers of radical Islam and Sharia law. Spencer has authored several books on Islam, including The Politically Incorrect Guide to Islam (and the Crusades) (2005), The Truth About Muhammad (2006), Stealth Jihad (2008), and The History of Jihad: From Muhammad to ISIS (2018), challenging mainstream narratives on Islamic history and doctrine.

In 2010, he co-founded the American Freedom Defense Initiative (AFDI) and Stop Islamization of America (SIOA) with Pamela Geller; he serves as vice president of AFDI and also holds the vice presidency at the American Freedom Law Center. Spencer’s activism includes free speech advocacy, media appearances, participation in documentaries such as Islam: What the West Needs to Know (2006), and film roles like Islamicize Me (2018). He has collaborated with counter-jihad figures, including Anders Gravers and Dutch politician Geert Wilders, and is affiliated with organizations like the Center for Security Policy and ACT for America.

Spencer has faced bans from Facebook and YouTube due to hate speech violations, legal challenges such as a 2015 lawsuit filed by the Metropolitan Transportation Authority over anti-Muslim subway ads (which was settled), regulatory scrutiny regarding AFDI’s nonprofit status, and was denied entry to the United Kingdom in 2013 because of his promotion of hate speech. Groups including the Southern Poverty Law Center, the Council on American-Islamic Relations, and the Anti-Defamation League have labeled him an Islamophobe. IRS filings from 2008 show he earned $132,537 from the David Horowitz Freedom Center. Despite controversies, Spencer remains a prominent figure in anti-Islamist networks and a leading voice in anti-Sharia and counterterrorism discourse, influencing public debate on immigration, terrorism, and religious freedom through his writings, speeches, and activism.