What is the origin of the surname 'Loeb'

From the German "Loewe," for "lion," I think. The German word is normally spelled "Lowe," with an umlaut on the "o."

From "Löwe" in German, which comes from "Levi" in Hebrew.

Are you sure the word Levi didn't come from the German Löwe?

Hebrew long predates German, and the name "Levi" is, of course, biblical. I think Arpeggionist must be right. But does "Levi" mean "lion" in Hebrew?

Levi means 'united' so I highly doubt Lowe came from Levi.

One possibility is this: in German, "w" is pronounced with a "v" sound. A Jew named Levi, settling in a German-speaking territory, might well have ended up with "Lowe" as his surname. Foreign names have frequently been adapted to local languages and their pronunciations.

Levi means to accompany or guide. The source of the name is from Genesis 29:34: "She became pregnant again, and gave birth to a son, and said: 'Now this time my husband will be at my side [Heb. "yilaveh 'ishi 'elai"], for I have given him three sons,' for that reason he called him Levi."

People named Levi are generally recognized as the descendants of this tribe, and like the rest of the Jewish people they scattered all over the world. So a few of them naturally found their way into small towns in Germany or Austria, where they simply transliterated their names (not very well). Levi became Löwe or Löbe, which became Loeb in the English speaking world.

Very nice, Arpeggionist. You explained it rather more elegantly than I did.

I just happened to have my book on hand. I'm terrible at remembering chapter and verse numbers.