狄奥多里克一世（Theodoric I，？－451年）是西哥特王国的一位国王，他统治的时间为418年至451年。

狄奥多里克一世是亚拉里克一世的私生子。418年，西哥特国王瓦利亚率部众自伊比利亚半岛迁往高卢，途中逝世，狄奥多里克一世继位。在位期间，对法兰克人和汪达尔人用兵，并与西罗马帝国结为同盟。

451年，西罗马、西哥特联军在沙隆平原与匈人、东哥特联军交战，狄奥多里克一世亲自参战，被东哥特人的标枪击中而阵亡。多里斯蒙德继承王位。

Theodoric I (Gothic:Þiudareiks; German:Theodorid or Theodorich; Latin:Theodericus), (c. 393 – 20 ******51) known in Spanish, Portuguese, and Italian as Teodorico, was the Germanic King of the Visigoths from 418 to 451 AD. An illegitimate son of Alaric, Theodoric is famous for his part in defeating Attila at the Battle of the Catalaunian Plains in 451, where he was killed.