Sextus Cocceius Severianus was a Roman senator who flourished during the reign of Antonius Pius. An unpublished military diploma attests that he was governor of Roman Arabia 12 August 145; Severianus was promoted to suffect consul in 147, with first Tiberius Licinius Cassius Cassianus then Gaius Popilius Carus Pedo as his colleague. Between 161 and 163 he was Proconsul of Africa
He married Caesonia; their known children include a son Sextus Cocceius Severianus; Sextus Cocceius Vibianus, (flourished c. 204) is a known grandson.