After graduating from high school, Dorfmann studied agricultural sciences in Piacenza and he started teaching in the agricultural school of Auer). He then became the head of the department for agriculture in the chamber of commerce in Bolzano. After that Dorfmann became the director of the South Tyrolean farmers' association, a position he occupied for nearly ten years. Dorfmann is married and father of two sons.
From 2005 to 2009, Herbert Dorfmann was elected mayor of Feldthurns. In the 2009 European election, Dorfmann was elected as a member of the European Parliament with the list of the South Tyrolean People's Party (SVP). He is a member of the group of the European People's Party (EPP), being also part of its governing board. Herbert Dorfmann furthermore holds the position of chairman of the South Tyrolean People's Party in the Eisacktal district and is therefore a member of the party's leadership and the party's executive committee.