[1] The nomen Rubellius belongs to a class of gentilicia formed using the diminutive suffix -ellius, typically derived from other gentile names.
In this case the root may have been a name such as Rubius, Rubrius, or Rufius, derived from ruber, reddish or ruddy, or rufus, red.
[2] The chief praenomina of the Rubellii were Gaius and Lucius, the two most common names throughout Roman history.
The main family of the Rubellii bore the surname Blandus, charming or flattering.
[3] One member of this family was known as Plautus, a common surname originally given to someone with flat or splayed feet.