“Greet Andronicus and Junia, my kin and my fellow prisoners, who are distinguished among the apostles, who were also in Christ before me” (Romans 16:7).
What can we know about Junia?
Junia is a Fellow Jew
Paul names both Andronicus and Junia as “kin” (συγγενεῖς/ syngeneis), which could mean that they are either fellow Jews or blood relatives of Paul. The apostle also names other persons on this list as “kin” (16:11, 17), which raises doubts that they all happen to be Paul’s actual relatives. He probably means that they are fellow Jews, as in Romans 9:3.
Junia is a Woman
Although several Greek manuscripts and a few early translations have “Julian” (Ιουλιαν) in this verse, Bruce Metzger and his textual committee unanimously reject this name as original. They favor Ἰουνιαν (Junia or Junias); the vast majority of manuscripts support this reading, though questions may be raised on how it was originally accented. In Metzger’s words, some members of the committee were “impressed by the facts that (1) the female Latin name Junia occurs more than 250 times in Greek and Latin inscriptions found in Rome alone, whereas the male name Junias [presumably a shortened form of Iunianus] is unattested anywhere, and (2) when Greek manuscripts began to be accented, scribes wrote the feminine Ἰουνίαν (“Junia”).”
According to Joseph Fitzmyer, a number of ancient commentators considered Junia (Iounian or Ioulian) to be the wife of Andronicus. John Chrysostom (c. 347–407), for example, said regarding Junia, “How great the wisdom of this woman that she was even deemed worthy of the apostles’ title” (Homilies on Romans, 31.2). According to Fitzmyer, Giles of Rome (1247–1316) first broke with earlier patristic tradition by interpreting “Andronicus and Julia(!) as two men (viri)..” Evidence thus points to Junia as a woman; she is probably married to Andronicus (unless his sister). Similar to Priscilla and Aquila (Romans 16:3), they are a couple dear to Paul.
Junia is a Fellow Prisoner
Paul considers Junia, along with Andronicus, to be “fellow prisoners.” The word here, synaichmalȏtos (συναιχμάλωτος), could hardly be metaphorical. Paul greets and uses the term to describe Aristarchus and Epaphras, respectively, in a literal sense (cf. Colossians 4:10; Philemon 23). Junia and Andronicus appear to have been imprisoned for their faith.
Junia has been a Follower of Christ longer than Paul
The husband and wife team became followers of Jesus Messiah before Paul. Richard Bauckham argues that Junia is Johanna from Luke 8:3. We do not know enough to affirm or deny such a claim.
Were Junia and Andronicus pivotal in first bringing the gospel to Rome? This is not at all far-fetched. Were they among the Hellenists with Stephen (Acts 6)? Were they with the original crowd that was baptized on the day of Pentecost (Act 2)? Does this couple go back as far as the 70 sent out in Luke 10? Might they be among the five hundred eye-witnesses of the resurrected Christ (1 Cor 15:6)? Paul mentions that an apostle is one who has seen the risen Lord; he assumes this as a criterion for authentication (1 Cor 9:1–2).
In any case, Junia and Andronicus were early disciples of Christ.
Junia is an Apostle
Paul says that Junia, along with Andronicus, are distinguished among the apostles. A few interpreters have taken this to mean that they were outstanding “in the judgement of” or “in the eyes of” the apostles. But the preposition en (ἐν) in this verse should be translated normally as “among.” This means that they were numbered with the apostles as apostles themselves.
The term “apostle” in Romans 16:7 probably should be understood in the normal sense of being a messenger who is sent out to start churches. Junia and Andronicus, to be sure, are not among the original Twelve Disciples of Jesus. Rather, they are the type of apostolic ministers comparable with Barnabas and Paul himself (1 Cor 9:5–6; cf. Acts 14:4, 14). An apostle would be considered on the top tier of authority as far as spiritual gifts are concerned (1 Corinthians 12:28; cf. Ephesians 4:11).
This verse stands out as an example that women in the earliest days of the Jesus Messiah movement possessed authoritative positions among believers.
For more resources on Junia, women in the Bible, and women in ministry, I recommend The Junia Project.
 Bruce M. Metzger, A Textual Commentary on the Greek New Testament. 4th ed. (London/ New York: United Bible Socities, 1994), 475. For an investigative study on how the change of names might have happened, see Rena Pederson, The Lost Apostle: Searching for the Truth about Junia (San Francisco: Jossey-Bass, 2008).
 Joseph A. Fitzmyer S.J., Romans, AYB 33 (New Haven; London: Yale University Press, 2008), 738.
 Richard Bauckham, Gospel Women: Studies in the Named Women of the Gospels (2002), 109–202.
 For example, the German scholar, Theodor Zahn, Der Brief des Paulus an die Römer (Leipzig, 1910), 608.