Leonhard von Eck was born in 1480 in Kelheim, a settlement on the River Danube west of Regensburg.
He studied at the universities of Ingolstadt and Siena where he obtained an MA and a doctorate of laws respectively. On his return to Germany, he was appointed tutor to William IV, the duke of Bavaria, and in 1519 became the chancellor of Bavaria, a position he held for the next 30 years.
In 1520 he married Felicitas von Freyberg, the widow of Dietrich von Plieningen, whose library he inherited.
Leonhard died in Munich on 17 March 1550 and was buried in his home town of Kelheim.