Joseph "Jo" Siffert (July 7, 1936 – October 24, 1971) was a Swiss racing driver. Affectionately known as "Seppi" to his family and close friends, Siffert was born in Fribourg, Switzerland, the son of a dairy owner. He initially made his name in racing on two wheels, powering his way to the Swiss 350 cc motorcycle championship in 1959, before switching to four wheels with a Formula Junior Stanguellini. Siffert graduated to Formula One as a privateer in 1962, with a four-cylinder Lotus-Climax. He later moved to Swiss team Scuderia Filipinetti, and in 1964 joined Rob Walker's private British Rob Walker Racing Team. Early successes included victories in the non-Championship 1964 and 1965 Mediterranean Grands Prix, both times beating Jim Clark by a very narrow margin. Siffert was married twice