Baitullah Mehsud (Pashto: بیت اللہ محسود; Urdu: بیت اللہ محسود; c. 1974 – August 5, 2009) was a leading militant in Waziristan, Pakistan, and the leader of the Tehrik-i-Taliban Pakistan (TTP). He formed the TTP from an alliance of about five militant groups in December 2007. He is thought by U.S. military analysts to have commanded up to 5,000 fighters and to have been behind numerous attacks in Pakistan including the assassination of Benazir Bhutto which he and others have denied.

Disagreement exists over the exact date of the militant's death. Pakistani security officials initially announced that Baitullah Mehsud, his wife and bodyguards were killed on 5 August 2009 in a U.S. Central Intelligence Agency drone attack in the Zangar area of South Waziristan. Interior Minister Rehman Malik delayed giving official confirmation and asked for patience and an announcement by Inter Services Public Relations (ISPR) or other agencies. Kafayat Ullah, a TTP source, also announced the death of the militant in the strike, as did his deputy Faqir Mohammed. Later Tehrik-i-Taliban Pakistan commander Hakimullah Mehsud denied previous TTP announcements and said Mehsud was in good health. Major General Athar Abbas, ISPR spokesman, and Robert Gibbs of the White House said his death could not be confirmed,U.S. National Security Adviser James L. Jones also claimed that there was "pretty conclusive" evidence that proved Baitullah Mehsud had been killed and that he was 90% sure of it. On August 25, 2009, Hakimullah Mehsud and Wali-ur-Rehman telephoned the BBC to say that the Baitullah Mehsud had died on August 23, 2009, due to injuries sustained during the August 5 attack. The BBC received a video that shows the body of Mehsud on September 30.