Sidi Mohamed Ould Cheikh Abdallahi (Arabic: سيدي محمد ولد الشيخ عبد الله‎; born 1938) is a Mauritanian politician who was President of Mauritania from 2007 to 2008. He served in the government during the 1970s, and after a long period of absence from politics he won the March 2007 presidential election, taking office on 19 April 2007. He was deposed in a military coup d'état on August 6, 2008.