Willis is an English given name derived from the Germanic name Willahelm, which means "will helmet" or "resolute protection." The name has its roots in the Old German words "wil" (will) and "helm" (helmet or protector).

The name Willis first appeared in England during the Middle Ages, around the 12th century. It was a common name among the Anglo-Saxons and became popular after the Norman Conquest of 1066.

One of the earliest recorded instances of the name Willis can be found in the Domesday Book of 1086, which was a survey of landowners in England commissioned by William the Conqueror. The name appeared several times in this historical record.

In the 13th century, Willis was mentioned in the Curia Regis Rolls, a collection of legal records from the royal court of England. The name was also found in various medieval charters and documents from that period.

Throughout history, several notable figures have borne the name Willis. One of the earliest was Willis de Braose (c. 1150-1210), a prominent Anglo-Norman baron and Lord of Gower in Wales.

Another historical figure was Willis Browne (1608-1692), an English clergyman and author who wrote several books on natural history and theology.

In the 18th century, Willis Hill (1718-1808) was an English mathematician and astronomer who made significant contributions to the field of celestial mechanics.

Willis Richardson (1819-1897) was an American politician and military officer who served as a general in the Union Army during the American Civil War.

Willis Carrier (1876-1950) was an American engineer and inventor, best known for inventing modern air conditioning.

While the name Willis has its roots in England and was primarily used in the English-speaking world, it has also been adopted in other cultures and languages over time. However, its origins can be traced back to the Germanic languages and the Old English period, when it first emerged as a given name for boys.