Manfred Schmid was born in Liezen, Styria in the middle of Austria. After using a luge every winter to go to school he became a member of WSV Liezen at the age of 12. His first top results came in doubles, when he twice won the European Junior Championships, in 1960 and 1962, with different partners. Schmid competed in four consecutive Olympics starting in 1964, but his greatest success came at the 1968 Games, when he won gold in the singles and silver in the doubles. Before this Games he was only able to win one medal in senior international competitions, a silver in the doubles together with Ewald Walch at the 1967 World Championships. In the following years he and his partner Walch were one of the best doubles team as they won gold at the World Championships in 1969 and 1970 and won silver in 1971. At the European Championships they won bronze in 1970 and silver in 1971. Schmid never won a singles title again, but won silver at the World Championships in 1969 and 1975 as well as bronze in 1978 and at the European Championships he won bronze in 1971 and silver in 1974. At the end of his career he also finished third in the inaugural Luge World Cup in 1977-78.
Schmid was a qualified machine fitter and, as was usual at that time, a true amateur, who had to take unpaid leave for his sport as he did during the 1968 Winter Olympics. In 1968 he became Styrian sportsmen of the year and was awarded the Ring of Honour of his hometown Liezen, who later also named a lane after him Manfred Schmid-Gasse. In 1996 he was awarded a Decoration of Honour in Gold for Services to the Republic of Austria. His brother Rudolf was also a successful luger and won bronze in doubles at the 1976 Olympics.