Nero Claudius Drusus Germanicus (14 January 38 BCE – 14 September 9 BCE), born Decimus Claudius Drusus, also called Drusus, Drusus I, Nero Drusus, or Drusus the Elder, is a Roman politician and military commander.

He is a fully patrician Claudian on his father's side but his maternal grandmother is from a plebeian family.

He is the son of Livia Drusilla and the stepson of her second husband, the Emperor Augustus.

He is also brother of the Emperor Tiberius, father of the Emperor Claudius, paternal grandfather of the Emperor Caligula, and maternal great-grandfather of the Emperor Nero.

He launches the first major Roman campaigns across the Rhine and begins the conquest of Germania, becoming the first Roman general to reach the Weser and Elbe rivers.

In 12 BCE, Drusus leads a successful campaign into Germania, subjugating the Sicambri.

Later that year he led a naval expedition against Germanic tribes along the North Sea coast, conquering the Batavi and the Frisii, and defeating the Chauci near the mouth of the Weser.

In 11 BCE, he conquers the Usipetes and the Marsi, extending Roman control to the Upper Weser.

In 10 BCE, he launches a campaign against the Chatti and the resurgent Sicambri, subjugating both.

The following year he conquers the Mattiaci, while defeating the Marcomanni and the Cherusci, defeating the latter near the Elbe.

However, Drusus dies later this year, depriving Rome of one its best generals.