Quintus Ligarius was a Roman soldier, circa 50 BC. He was accused of treason for having opposed Julius Caesar in a war in Africa, but was defended so eloquently by Cicero that he was pardoned and allowed to return to Rome. He later conspired with Brutus in the assassination of Julius Caesar.
Ligarius is a character in William Shakespeare's tragedy Julius Caesar. He is depicted as a sickly man, though strong in mind, with a grudge against Caesar for reprimanding him for admiring Pompey.