Lämmert was born September 20, 1924, in Bonn and died May 3, 2015, in Berlin. After a period as a British prisoner of war, he studied geology and mineralogy as well as German language and literature, history, and geography.
From 1961 to 1970, Lämmert was a professor of German language and literature at Freie Universität. He left the university in 1970 in order to take a position as a professor of general literature in Heidelberg. Lämmert returned to Freie Universität in 1976, when the council elected him the university’s second president. From 1983 until his retirement, in 1992, he remained at Freie Universität Berlin as a professor of general and comparative literature.
Lämmert remained active during his retirement, serving in various capacities, including as the president of the German Schiller Society (Deutsche Schillergesellschaft) from 1988 to 2002 and as the president of the German Literature Archive in Marbach as well as being a member of the Board of the German Academic Exchange Service (DAAD).