This interesting and unusual name has two possible sources, each with its own distinct history and derivation.
Firstly, the surname may be of Old French origin, and an occupational name for a forester, introduced into England after the Norman Conquest of 1066. The derivation is from the Anglo-Norman and Old French "warde(r)", to guard, and "bois", wood.
Secondly, the surname may be of Old Scandinavian origin, and a variant of the locational name Warboys, from the place so called in the former county of Huntingdonshire, now part of Cambridgeshire, and a parish in the diocese of Ely.
The placename is recorded in the Saxon Chartulary of 974 as "Wardebusc, Weardebusc", and is composed of the Old Norse elements "varthi", beacon, and "buski", brushwood, bushes.
Job-descriptive surnames originally denoted the actual occupation of the namebearer, and gradually became hereditary, while locational surnames were used particularly as a means of identification by those who left their birthplace to settle elsewhere.
The modern forms of the surname from either source include, Warboy(s), Worboy(s), Warb(e)y(s) and Wharby, and some early examples are Warbye (1569); Warby (1575); Warbie (1633); and Warebe (1634). Among the recordings of the name in Church Registers is the marriage of Anne Warby and John Crouchley at St. Dunstan in the East, London, on October 16th 1575. The first recorded spelling of the family name is shown to be that of Richard Wardebois, which was dated 1207, in the "Pipe Rolls of Staffordshire", during the reign of King John, known as "Lackland", 1199 - 1216.
Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.