Marc Ernest Peter (French pronunciation: [mark ɛʁ.nɛst pe.tɛʁ]; 21 December 1873 – 5 September 1966) was a Swiss attorney, author, politician and diplomat.

He did also serve as judge, city president of Versoix and the Grand Council of Geneva.

Subsequently, Peter was the Minister to the Mission of Switzerland to the United States in Washington, D.C., succeeding Hans A. Sulzer from 1920 to 1939.

Peter remained in the United States until 1946, where he lastly was the representative for the International Committee of the Red Cross.

After holding several public offices in Switzerland, Peter was appointed Minister to the Mission of Switzerland to the United States in Washington, D.C., serving between 25 December 1919 and 30 November 1939.