Theudebert II (French: Thibert or Théodebert), King of Austrasia (595–612 AD), was the son and heir of Childebert II. He received the kingdom of Austrasia plus the cities (civitates) of Poitiers, Tours, Le Puy-en-Velay, Bordeaux, and Châteaudun, as well as the Champagne, the Auvergne, and Transjurane Alemannia.
He succeeded his grandmother Brunhilda.
In 599, Theudebert and his brother Theuderic II were at war. Theuderic defeated him at Sens, but then allied against their cousin Chlothar II and defeated him at Dormelles (near Montereau), thereby laying their hands on a great portion of Neustria (600–604). At this point, however, the two brothers took up arms against each other; Theuderic defeated him at Étampes and he refused to aid his brother when Theuderic's kingdom was invaded by Clotaire in 605. In 610, he extorted Alsace from his brother and Theuderic took up arms against him, yet again.
Theudebert was defeated handily at Toul and at Zülpich in 612. Bishop Ludegast of Mainz is said to have beseeched his brother in a fable to spare his life. He was locked up in a monastery at the order of his grandmother, and assassinated with his son Merovech.
His daughter Emma is sometimes thought to have married Eadbald of Kent.