(born 1962) is an American author and blogger best known for Criticism of Islam and research into Islamic terrorism and jihad.

In August 2010 The Washington Post cited Spencer, along with Pamela Geller as conservative bloggers who have been influential in challenging the construction of the Park51 project, which he calls the "Ground Zero mosque". Spencer and Geller's organization Stop Islamization of America launched their first public protest outside of the Park51 location on June 6, 2010.