Marta Kos (Slovene pronunciation: [ˈmáːrta ˈkóːs]; born 28 June 1965) is a Slovenian diplomat and politician.

[2] Ahead of the 2022 presidential election, she was the candidate of the Freedom Movement for president of Slovenia until her withdrawal in August.

[5] In 2013, the government of Alenka Bratušek appointed her Ambassador to Berlin, Germany, as part of a political quota (non-career diplomats).

[8] In 2020, she resigned as ambassador due to disagreement with the government's foreign policy, as well as accusations of mobbing and consequental internal control over the work of the embassy.

[13] Kos is married to Henri Gétaz, who is the secretary general of the European Free Trade Association.