Question: Did King Solomon marry the Queen of Sheba and was she a black woman?
Answer: Where Sheba was from is a matter of contention. Abarbanel maintains it was Yemen, while Meam Loez argues it was Ethiopia, which would support the legend that she was black. Most commentaries to Kings (see Kings 1 10:14) explain that Solomon did not marry her. Arizal though, is purported to have said that the queen was converted and had a child from King Solomon who was an ancestor to Nebuchadnezzar, the evil king who destroyed the first Temple.
I have heard the argument that the conversion of the Queen of Sheba would explain the existence of black Jews who are of Ethiopian ethnicity. However, this theory of the origin of Ethiopian Jewry is baseless, albeit interesting. A few years ago I made the acquaintance of a young Ethiopian transfer student who was studying in a university in the United States, and was to return home after completing his degree. He told me that the meeting between the Queen of Sheba and King Solomon is ancient folklore in their tradition (with a few modifications to glorify the queen). It is surely one of the more intriguing episodes in the prophets.
Rabbi Shlomo Soroka