Tudhaliya III was a short-lived king of the Hittite Empire (New Kingdom) ca. 1344 BC (short chronology); he may have been the son and successor of Hattusili II, however he is normally viewed as the son and immediate successor of Tudhaliya II (according to the king count used here). He is never explicitly known to have been king at all. The Hittite texts refer to him as "Tudhaliya the child" or, as an alternate translation, "Tudhaliya the Young(er)". He was killed by a group of officers that included his successor, and quite probably brother, Suppiluliuma I.
There is some difficulty concerning numbering of the Tudhaliyas (and Hattusilis) of the Hittite empire. This Tudhaliya is normally not included in Hittite king lists, and his father will often be seen listed in modern literature as Tudhaliya III.