AD 38 (XXXVIII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Iulianus and Asprenas (or, less frequently, year 791 Ab urbe condita). The denomination AD 38 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

• Claudius and Messalina are most likely married at this point in time.
• Apion heads a deputation to Emperor Caligula, to complain about the Jews in Alexandria.
• An anti-Jewish riot breaks out in Alexandria, during a visit by King Herod Agrippa I; the mob wants to place statues of Caligula in every synagogue.

• An epidemic breaks out in K'aui-chi, causing many deaths. Imperial official Ch'ung-li I provides medicines that save many lives.^{[citation needed]}

• Phaedrus writes his popular collection of fables.

• Paul meets Peter and James in Jerusalem (approximate date) (After 3 years "from his vision on the road to Damascus " went to Jerusalem to meet Peter and stayed 15 days with him.(Epistle to Galatians chapter a 18)
• Andrew the Apostle becomes the first patriarch of Constantinople, and resigns that position shortly thereafter.
• Stachys the Apostle becomes the second patriarch of Constantinople.

• Drusilla, Jewish princess and daughter of Herod Agrippa I (d. AD 79)
• Drusilla, princess of Mauretania
• Julius Archelaus Antiochus, prince of Commagene (d. AD 92)
• Lucius Calpurnius Piso Licinianus, Roman co-emperor (d. AD 69)
• Marcus Valerius Martialis, Roman Latin poet (approximate date)

• June 10 – Julia Drusilla, sister of Caligula (b. AD 16)^[1]
• Archelaus of Cilicia, Roman client king
• Du Shi, Chinese inventor and politician
• Ennia Thrasylla, Roman noblewoman
• Naevius Sutorius Macro, Roman prefect (b. 21 BC)
• Rhoemetalces II, Roman client king
• Tiberius Gemellus, grandson of Tiberius (b. AD 19)
• Tiberius Julius Aspurgus, Roman client king