Ali Abdullah Saleh al-Ahmar (Arabic: علي عبدالله صالح الأحمر , ʿAlī ʿAbdullāh Ṣāliḥ al-Aḥmar; 21 March 1947 – 4 December 2017) was a Yemeni politician who served as the first President of Yemen, from Yemeni unification on 22 May 1990 to his resignation on 25 February 2012, following the Yemeni Revolution. Previously, he had served as President of the Yemen Arab Republic, or North Yemen, from July 1978 to 22 May 1990, after the assassination of President Ahmad al-Ghashmi.

Saleh developed deeper ties with Western powers, especially the United States, in the War on Terror. Islamic terrorism may have been used and encouraged by Ali Abdullah Saleh to win Western support and for disruptive politically motivated attacks. In 2011, in the wake of the Arab Spring, which spread across North Africa and the Middle East (including Yemen), Saleh's time in office became increasingly precarious until eventually he was ousted as president in 2012. He was succeeded by Abdrabbuh Mansur Hadi, who had been vice-president since 1994.

In May 2015, Saleh openly allied with the Houthis (Ansar Allah) during the Yemeni Civil War, in which a protest movement and subsequent insurgency succeeded in capturing Yemen's capital, Sana'a, causing President Abdrabbuh Mansur Hadi to resign and flee the country. In December 2017, he declared his withdrawal from his coalition with the Houthis and instead sided with his former enemies – Saudi Arabia, the United Arab Emirates and President Hadi.

On 4 December 2017, during a battle between Houthi and Saleh supporters in Sanaa, the Houthis accused Saleh of "treason", and he was killed by a Houthi sniper. Reports were that Saleh was killed while trying to flee his compound in a car; however, this was denied by his party officials, who said he was executed at his house.