This List of Targums is based upon a list given here, these are older works (No later than 1930), but they are easily accessible.
Targum of Canticles
Exposition of the Book of Solomon’s Song by J. Gill (2nd Edition 1751) contained a translation of the Targum, which I’ve been unable to locate.
A newer translation (still old) of the 1st chapter is found in C.D. Ginsburg commentary on Song of Songs (1857) on pages 29-33
A translation may also be found in the series Translations from Hebrew and Aramaic with the volume by H. Gollancz (1908) on pages 15-90
Second Targum on Esther / Targum Sheni of Esther
This is found in the English translation of P.S. Cassel’s commentary An Explanatory Commentary on Esther tr. A. Bernstein (1888) found on pages 263-344.
Targum of Qoheleth
Found in Coheleth, Commonly called the Book of Ecclesiastes in 1861, by C.D. Ginsburg on pages 502-519
Targum Onkelos and Jonathan on the Pentateuch
J.W. Etheridge The Targum of Onkelos and Jonathan Ben Uzziel on the Pentateuch with the Fragments of the Jerusalem Targum (2 Volumes 1862-1865)
Targum of Isaiah
Found in The Chaldee Paraphrase of the Prophet Isaiah by C.W.H. Pauli in 1871
Targum of Ruth
A translation of the Targum of Ruth may be found in Studia orientalia volume 2 (1928) by A Saarisalo on pages 88-104
Older Translations that I’m unable to find
I have been unable to locate these works, which should be public domain by now. If anyone can point me to them, it would be appreciated.
Targum on Song of Songs
As noted above a Targum of Canticles is found in the work Exposition of the Book of Solomon’s Song by J. Gill (2nd Edition 1751) Unfortunately I cannot find an early enough edition on the internet, Gill’s later editions of this commentary took it out.
Later edition can be Found Here, it still references the Targums a lot.
Targums of Ruth and Jonah
From O.T. Crane (1886) in The Targums on the Books of Ruth and Jonah: Literally translated from the Chaldee.
Targum on Lamentations
In 1893 by A.W. Greenup, The Targum on the Book of Lamentations
The following are online translations that I have found. http://targum.info/ has been particularly helpful. If there are any other online English translations, please leave a comment
a new translation by Edward M. Cook, 2001
A Translation by Thomas Lenihan, 2015
Targumim of the Megillot
Song of Songs
A Translation by Jay C. Treat, 2004
A translation by Samson H. Levey, 1998
And a Translation by C.M.M. Brady, 2016
Translation by C.M.M. Brady, 2008
Sefaria also seems to have some Targums translated
Here’s a quick list of online resources for the Targums in their original language, I’m sure there’s more, but didn’t bother to look
This List was last updated 3/15/2018, with some additions and fixed links. If there are any broken links, please leave a comment.