Judah III is a famous Jewish sage mentioned in the classical works of Judaism's oral law, who lived during the third and beginning of the fourth century CE. He figures in the Mishnah and Talmud. He was the son of Gamaliel IV , and grandson of Judah II.

It is often difficult to know when the Mishna and Talmud are referring to Judah II or Judah III; they do not clearly distinguish between them. Since the title "Nesi'ah" was borne by both, which of the two in any citation is meant by "Judah Nesi'ah" can be gathered only from internal evidence, especially from the names of the scholars mentioned in the context.

Judah III held the office of patriarch probably during the close of the third and the beginning of the fourth century. He was a pupil of Johanan (Mishnah) (d. 279); in a question regarding the time of the new moon, which he sent to Ammi (Mishnah) , he introduces a sentence taught to him by Johanan with the words: "Know that R. Johanan has taught us thus all his life long" (R. H. 20a).

Judah III. commissioned Johanan's pupils Ammi and Assi , who directed the Academy of Tiberias after Eleazar's death, to organize the schools for children in the Palestinian cities (Yer. Ḥag. 76c; Pesiḳ. 120b); Ammi especially appears as his councilor in haggadic questions (Beẓah 27a; M. Ḳ. 12b, 17a; 'Ab. Zarah 33b).