Sven Mikser (born 8 November 1973) is an Estonian politician.
As a member of the Estonian Centre Party from 2002 to 2003, Mikser served as the minister of defence in the Siim Kallas' cabinet.
Mikser was the leader of the Social Democratic Party between 16 October 2010 and 30 May 2015. He has been the Minister of Defence since 26 March 2014 in Taavi Rõivas' first and second cabinets. On 23 November 2016 he assumed the position of Minister of Foreign Affairs in the cabinet of Jüri Ratas.
Mikser was elected as a Member of the European Parliament in 2019. He has since been serving on the Committee on Foreign Affairs and its Subcommittee on Security and Defence. In addition to his committee assignments, he is part of the Parliament's delegation to the Euronest Parliamentary Assembly and to the NATO Parliamentary Assembly.