The name Oswaldo has its origins in the Germanic languages, derived from the Old Norse elements "os" meaning "god" and "waldan" meaning "to rule" or "to govern." It is a variant of the name Oswald, which was borne by several historical figures.

The earliest recorded instance of the name Oswald dates back to the 7th century, when it was the name of a Northumbrian king who ruled from 634 to 642 AD. He was later venerated as a saint and martyr after his death in the Battle of Maserfield.

Another notable figure with the name Oswald was Oswald of Worcester, an Anglo-Saxon bishop who lived in the 10th century. He played a significant role in the revival of monastic life in England during his time as Bishop of Worcester and Archbishop of York.

In the 12th century, Oswald of Gloucester was a renowned English hagiographer and author. He wrote the life of St. Wulfstan, the Bishop of Worcester, and other works that shed light on the religious and cultural life of the time.

During the 16th century, Oswald Myconius was a Swiss Protestant reformer and theologian. He was a close associate of Huldrych Zwingli and played a crucial role in the spread of the Protestant Reformation in Switzerland.

In more recent history, Oswaldo Aranha (1894-1976) was a Brazilian diplomat and politician who served as the Minister of Foreign Affairs and as a representative at the United Nations. He played a significant role in the establishment of the United Nations and was the first President of the United Nations General Assembly.

While the name Oswaldo has Germanic roots, it has been adopted and used in various cultures and languages, particularly in Spanish-speaking countries. Its popularity has waxed and waned over the centuries, but it remains a recognizable name with a rich historical legacy.