The name Lionel has its origins in the ancient Germanic languages. It is derived from the Germanic elements "leo" meaning lion and "hart" meaning brave or hardy. The name can be traced back to the 12th century and the Old French form "Lion".

In its earliest known uses, the name Lionel referred to someone with lion-like qualities of strength, courage and bravery. It was a popular name among nobility and royalty in medieval times across Europe. Some early examples include Lionel of Antwerp, 1st Duke of Clarence, who lived from 1338 to 1368 and was the second eldest son of King Edward III of England.

The name Lionel appears in various historical accounts and literature from the Middle Ages. It is found in Geoffrey Chaucer's 14th century works, including The Canterbury Tales. Over time, variations like Lyonel and Lionelle emerged, but the modern standard spelling of Lionel became the most widely used form.

Some notable historical figures named Lionel include Lionel Tertis, a renowned English violist and composer from 1876 to 1975. Lionel Logue was an Australian speech therapist from 1880 to 1953, best known for helping King George VI overcome his stammer. Lionel Trilling was an influential American literary critic and author from 1905 to 1975. Lionel Hampton, an American jazz musician and bandleader, lived from 1908 to 2002.

Another famous bearer of the name was Lionel Messi, the Argentine professional football player born in 1987. He is widely regarded as one of the greatest players of all time and has won numerous awards and accolades throughout his career, including seven Ballon d'Or awards.