| Theuderic III | |
| King of the Franks | |
| Succession: | King in Neustria and Burgundy |
| Reign: | 673 |
| Predecessor: | Chlothar III |
| Successor: | Childerich II |
| Reign1: | 675–691 |
| Predecessor1: | Childeric II |
| Successor1: | Clovis IV |
| Succession2: | King in Austrasia |
| Reign2: | 679-691 |
| Predecessor2: | Dagobert II |
| Successor2: | Clovis IV |
| Spouse: | Chrothildis Amalberga |
| Issue: | Clovis IV Childebert III Clovis III (?) |
| House: | Merovingian |
| House-Type: | Dynasty |
| Father: | Clovis II |
| Mother: | Balthild |
| Birth Date: | c. 651 |
| Death Date: | c. |
Theuderic III (also spelled Theuderich, Theoderic or Theodoric; French: Thierry, c. 651–691) was King of the Franks in the 7th century. He ruled Neustria and Burgundy on two occasions (in 673 and again from 675 to 691), as well as Austrasia from 679 until his death in 691.
The son of Clovis II and Balthild, Theuderic has been described as a puppet ruler – a roi fainéant. After the death of his older brother Chlothar III, he was appointed King in Neustria by Ebroin, Mayor of the Palace, in 673, though Childeric II of Austrasia displaced him soon thereafter. After Childeric II was killed in 675, Theuderic II retook the throne. He subsequently fought a war against Dagobert II, with his forces under Ebroin victorious at the Battle of Lucofao. After Dagobert was murdered in 679, Theuderic was also recognized as king in Austrasia as well.
He and the Neustrian mayor of the palace, Waratton, made peace with Pepin of Heristal, mayor of the palace of Austrasia, in 681. However, on Waratton's death in 686, the new mayor, Berchar, made war with Austrasia and Pepin vanquished the Burgundo-Neustrian army under Berchar and Theuderic (a Neustrian) at the Battle of Tertry in 687, thus paving the way for Austrasian dominance of the Frankish state.
Theuderic married Chrothildis-Chrodechild Königin der Franken, a daughter of Ansegisel and Saint Begga of Landen.
They had the following children:
He married Amalberge (Saint Amalaberga) before 674, daughter of Wandregisis and Farahild.