He studied law and philosophy in the University of Lausanne, the University of Tubingen and Heidelberg University. He finished his education in Paris and then worked as a lecturer of Roman law in the University of Lausanne.
Fornerod’s political career began in 1845. He worked as a chancellor in the Grand Council of Vaud. The Federal Assembly chose him as a successor to the late Daniel-Henri Druey in the Council of States on July 11, 1855. He received 84 votes out of 148. During his career Fornerod headed several departments including Political Department, Military Department, Department of Defense, Department of Finance, Department of trade and Customs. In 1857, 1863 and 1867 he was elected President of Swiss Confederation. Fornerod also took part in the expansion of Swiss diplomatic representation in foreign countries (in particular in Berlin and Turin).
In 1863 Fornerod was involved in the foundation of the Swiss Bank, the predecessor of the Swiss National Bank.
On October 31, 1867, Fornerod resigned and handed over his position to Victor Ruffy. In the same year he took the leadership of Crédit Franco-Suisse, the financial services company headquartered in Geneva, later he moved to Paris. In 1870 the company went bankrupt and Fornerod was found guilty and sentenced to a long-term imprisonment. After his return to Switzerland he found a job of an ordinary worker on the railway line Jura-Simplon. He lived with his brother Justin, a former priest, on his farm in Bettens. After Justin’s death Fornerod led a lonely and isolated life as a pensioner till his death at the age of 80.