The Julio-Claudian dynasty normally refers to the first five Roman Emperors: Augustus, Tiberius, Caligula (also known as Gaius), Claudius, and Nero, or the family to which they belong; they rule the Roman Empire from its formation, in the second half of the 1st century (44/31/27) BCE, until CE 68, when the last of the line, Nero, commits suicide.

None of the Julio-Claudians are succeeded by their sons; only one of them has a legitimate son survive him.

The ancient historical writers, chiefly Suetonius and Tacitus, write from the point of view of the Roman senatorial aristocracy, and portray the Emperors in generally negative terms, whether from preference for the Roman Republic or love of a good scandalous story.