Rav Acha bar Yosef (Hebrew: אחא בר יוסף) was a fourth-generation Babylonian Amora.
[1] He was also a student of Rav Chisda, a second- or third-generation Amora.
[2][3] There is a dispute about whether the Amora named Rav Acha barei deRav Yosef is the same person.
However, Aaron Hyman, in "Toledot Tannaim veAmoraim," claims this is a mistake.
Hyman writes that Rav Acha barei deRav Yosef was a student of Rav Ashi, a sixth-generation Amora, and would frequently ask him questions.