Ahmet Necdet Sezer, Turkish judge and politician, 10th President of the Republic of Turkey

Ahmet Necdet Sezer (Turkish pronunciation: [ah'med nedʒ'det se'zæɾ]; born 13 September 1941) is a Turkish statesman and judge who served as the tenth president of Turkey from 2000 to 2007. Previously he was the president of the Constitutional Court of Turkey in 1998. The Grand National Assembly of Turkey elected Sezer as president in 2000 after Süleyman Demirel's seven-year term expired. He was succeeded by Abdullah Gül in 2007.

Following his legal career, Sezer became a candidate for the Presidency jointly supported by many political parties in Parliament. Following the 2000 presidential election, he took an ardent secularist approach on issues such as the headscarf and held the view that secularism in Turkey was under threat. A quarrel between Sezer and the Prime Minister Bülent Ecevit in 2001 led to a financial meltdown, attributed to the weakness of the coalition government as well as the existence of a large amount of debt to the International Monetary Fund.

The landslide victory of the conservative Islamist Justice and Development Party (AKP) in the 2002 general election resulted in strong opposition from President Sezer, who vetoed several laws and referred some to the Constitutional Court. These included laws on banking reform and the lifting of Recep Tayyip Erdoğan's political ban. During receptions at the presidential palace, Sezer refused to allow women wearing the headscarf to attend per the laws on separation of mosque and state at the time, resulting in the wives of Abdullah Gül and Erdoğan, Hayrünnisa Gül and Emine Erdoğan respectively, not attending the events. Erdoğan later publicly stated that he had 'suffered a lot' from Sezer.During the 2014 presidential election, ultimately won by Erdoğan, Sezer openly refused to vote, citing the lack of a secularist candidate as his reason.