Holenstein studied law at the University of Bern, finishing in 1920.
Politically, he was affiliated to the Christian Democratic People's Party of Switzerland.
From 1930 to 1935 he was president of the young conservative movement of the canton of St. Gallen.
During his time in office he headed up the Federal Department of Economic Affairs and was President of the Confederation in 1958.
He resigned on 20 November 1959 for health reasons and handed over office on 31 December 1959.