Decimus Junius Brutus Callaicus was a consul of the Roman Republic for the year 138 BC together with Publius Cornelius Scipio Nasica Serapio. He was an optimate politician and a military commander in Hispania and in Illyria. He was the son of Marcus Junius Brutus and brother of Marcus Junius Brutus. He had a son also named Decimus Junius Brutus and his grandson was Decimus Junius Brutus Albinus.

Hispania Ulterior was a Roman province located in Hispania during the Roman Republic, roughly located in Baetica and in the Guadalquivir valley of modern Spain and extending to all of Lusitania and Gallaecia. Its capital was Corduba.