In Masechet Megilah 3a, we find “Rabbi Yirmiyah (alt: Rabbi Chiya bar Abba) said, ‘The translation of the Torah was made by Onkelos the Convert, that he learned from Rabbi Eliezer and Rabbi Yehoshua. The translation of the Prophets was made by Yonatan ben Uziel, who learned it from the Prophets Chaggai, Zechariah and Malachi. At that time, Eretz Yisrael shuddered 400 parsah (Persian mile) by 400 parsah. A Heavenly Voice was heard, saying ‘Who is it that dared to reveal My secrets to human beings?’ Yonatan ben Uziel stood up and said, ‘I am the one who revealed Your secrets to human beings. But You know very well that I did it not for my own honor, nor for the honor of my father’s house, but rather I did it for Your Honor, in order to minimize arguments within the People of Israel.’ ” (Rashi explains this as a reference to arguments about the meaning of obscure verses)
The Gemara in Masechet Megila continues, “He (Yonatan ben Uziel) wanted to reveal the interpretation of the Holy Scriptures…” (the reference being to the following subset of the “K’tuvim:” The Books of Daniel, Ezra, Nechemiah and Divrei HaYamim I and II. “…A Heavenly Voice was heard, saying ‘You have gone far enough! Because the time of the Coming of the Mashiach is revealed there.’ ” (Rashi explains that this time, not to be revealed in advance, is revealed in a secretive manner in the Book of Daniel)
The Gemara continues the discussion, probing as to the difference between the Targum of Onkelos, which elicited no shuddering on the part of Eretz Yisrael, while the translation of the Prophets by Yonatan ben Uziel did. The Gemara answers that the Torah is meant to be an “open book,” with a clear meaning available to anyone who puts in the effort to learn it, while the Books of the Prophets, who often communicated their visions in difficult, even undecipherable, poetic language, are not meant to be “open books” in that sense. The Gemara cites an example: In Zechariah (12:11) we find, “On that day there shall be great mourning in Jerusalem, like the mourning of Hadadrimmon in the Valley of Megiddon.” And Rav Yoseph said, “Were it not for the translation, I would have no way of understanding its meaning…,” because Hadadrimmon has no obvious connection with the Valley of Megiddon. However, the Targum of Yonatan ben Uziel explains two cases of mourning: 1) the mourning of Achav the son of Omri, who was slain by Hadadrimmon, the son of Tadrimmon, in Ramot Gilad (I Melachim 22:36) and 2) the mourning by the Prophet Yirmiyahu of King Yoshiyahu, son of Amon, who was slain by the Lame Pharaoh in the Valley of Megiddon, as described in II Divrei HaYamim (35:25)
Thus, in summary, we have the Targum ascribed to Yonatan ben Uziel, that he received by tradition from the last of the Prophets, on sixteen Books of the Tanach, excepting the Five Books of Moses for which we have Targum Onkelos, and the Books of Daniel, Ezra, Nechemiah and Divrei HaYamim, which were purposely not translated.