Mehmet Zeki Sezer (born 12 April 1957) is a Turkish politician and former chairman of the Democratic Left Party (Demokratik Sol Parti, DSP), he was elected in the 6th ordinary party congress in 2004 after the resignation of Bülent Ecevit.

He graduated from M. Rüştü Uzel Chemistry Vocational High School and then from the School of Chemical Engineering at Gazi Üniversitesi in Ankara.

During his high school and university years, Sezer played volleyball for various clubs.

Sezer began his career as a chemistry technician in 1975 in the public service and later worked as a chemical engineer.

In 1999, Sezer was elected as deputy of Ankara to the Parliament and served as a minister of state in the 57th government under the Prime minister Bülent Ecevit [2] Sezer is married and has two children.