Theuderic III (also spelled Theuderich, Theoderic or Theodoric; French: Thierry, c. 651[1]–691) was King of the Franks in the 7th century.

The son of Clovis II and Balthild,[2] 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,[2] though Childeric II of Austrasia displaced him soon thereafter.

He subsequently fought a war against Dagobert II, with his forces under Ebroin victorious at the Battle of Lucofao.

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.