Decimus Junius Brutus Callaicus (or Gallaecus or Callaecus) (180 BC113 BC) 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 (consul in 178 BC) and brother of Marcus Junius Brutus (praetor in 88 BC). He had a son also named Decimus Junius Brutus (consul in 77 BC) and his grandson was Decimus Junius Brutus Albinus.