No. Saint Jude, traditionally called Jude Thaddeus, is not Judas Iscariot, the apostle who betrayed Jesus. The similar names can be confusing, especially when a Bible translation uses Judas for both men.
The clearest place to begin is the list of apostles in Luke. You do not need to untangle every later tradition to see that Luke names two different people.
Luke names two apostles called Judas
Near the end of the list, Luke names “Judas the son of James, and Judas Iscariot” (Luke 6:16, NABRE). Both appear in the same verse, and Luke identifies Iscariot as the one who became a traitor. The wording distinguishes the two men; it does not give one man two surnames. Read the complete passage in Luke 6 to see the names in context.
This is a useful habit whenever biblical names become confusing: look for the identifying words attached to a name. Here, “son of James” and “Iscariot” do important work. A shared first name does not establish a shared identity.
Why is Saint Jude also called Thaddeus?
The names in the Gospel lists are not identical. Matthew and Mark name Thaddeus; Luke names Judas the son of James. In his audience on Simon and Jude, Benedict XVI explains that tradition brings these names together as Jude Thaddeus, distinct from Judas Iscariot.
That explains why a church, devotional image or biography may say Saint Jude, Saint Thaddeus or Saint Jude Thaddeus. In this devotional setting, the names refer to the apostle honored as a saint, not to Iscariot.
Benedict also notes that explanations of the nickname Thaddeus are uncertain. It is better to acknowledge that limit than to turn an appealing name meaning into a proven fact about the apostle's character.
What about Judas at the Last Supper?
John 14:22 describes a question from a Judas whom the Gospel explicitly distinguishes from Iscariot. Benedict XVI follows the traditional identification of that speaker with Jude Thaddeus.
Keep the distinction between the text and its interpretation clear. John's wording excludes Iscariot; identifying the speaker more precisely involves interpretation. The identification with Jude belongs to the traditional reading Benedict presents, rather than something established by the name Judas alone.
You can therefore read the exchange thoughtfully without making it carry more historical certainty than it provides. The question concerns how Jesus will make himself known. Attend to Jesus' response in the surrounding passage, rather than stopping at the unfamiliar name.
How much else do we know about Saint Jude?
Benedict emphasizes how little historical information survives about this apostle. A later painting can help people recognize a devotional figure, but it is not a contemporary portrait or independent evidence for every detail of his life.
The Church commemorates Saints Simon and Jude on October 28. If you are preparing for that day, begin with what the biblical lists actually say, then distinguish later traditions when you encounter them. Our Saint Jude Thaddeus biography provides a starting point for further reading.
A simple way to keep the names straight
Read the whole list
Open Luke 6:12–16. Notice that Jesus chooses the Twelve after a night of prayer. Read all the names before returning to verse 16. This keeps the question within the story of Jesus calling his apostles.
Keep each identifier attached
In your notes, write Jude Thaddeus for the saint and Judas Iscariot for the betrayer. When reading Luke's wording, retain Judas the son of James. You are recording the distinction, not correcting the Bible's choice of name.
Ask what kind of claim you are reading
Does a statement come directly from a biblical passage, from a traditional identification, or from later devotional storytelling? These can serve different purposes. Naming the difference lets you appreciate a tradition without presenting every detail as documented history.
If Saint Jude becomes part of your prayer life, this clarification can remove an unnecessary worry: devotion to Jude Thaddeus is not devotion to Judas Iscariot. Start with the right person, and let careful reading deepen your understanding.