As an English name, Caleb came into use after the Protestant Reformation. It was common among the Puritans, who introduced it to America in the 17th century.
It has occasionally been used as an English given name since the 16th century. It was moderately popular in the 1940s, but had a more notable upswing in the early 2000s. This may have been inspired by the Spanish actress Penélope Cruz (1974-), who gained prominence in English-language movies at that time. It was already rapidly rising when celebrities Kourtney Kardashian and Scott Disick gave it to their baby daughter in 2012.
This name was initially more common among Eastern Christians, though it came to the West by the Middle Ages. It was borne by six kings of France and five kings of Spain. It was regularly used in England during the Middle Ages, although the Spanish king Philip II, who attempted an invasion of England, helped make it less common by the 17th century. It was revived in the English-speaking world in the 19th century. Famous bearers include the Elizabethan courtier and poet Philip Sidney (1554-1586) and the American science fiction novelist Philip K. Dick (1928-1982).