The name Marlo has its origins in the Italian language, deriving from the Latin name Marius. It is believed to have originated during the Roman Empire, as Marius was a prominent Roman family name.

Marius was a Latin praenomen, or personal name, that may have derived from the Latin word "mas," meaning male or masculine. It was a popular name among Roman families, particularly those of high social status.

One of the earliest and most notable historical references to the name Marius is Gaius Marius, a Roman general and statesman who lived from 157 BC to 86 BC. He was a prominent figure in the Roman Republic and played a significant role in the Jugurthine War and the Cimbric War.

Another famous bearer of the name Marius was Pope Marius I, who served as the Bishop of Rome from 308 to 309 AD. He is known for his efforts to maintain unity within the early Christian church during a period of persecution.

In the Middle Ages, the name Marlo emerged as a variant of Marius, particularly in Italy. One of the earliest recorded examples of this variant was Marlo Carletti, an Italian merchant and explorer who lived in the 16th century and traveled to the East Indies.

During the Renaissance period, the name Marlo gained popularity among Italian artists and intellectuals. Marlo Fiore, an Italian painter and architect who lived from 1470 to 1528, was a notable figure of this time.

In the 19th century, the name Marlo became more widespread across Europe and was adopted in various languages and cultures. Marlo Prévost, a French writer and literary critic, lived from 1809 to 1892 and was a prominent figure in the Romantic movement.

As the name Marlo spread, it was used by individuals from different backgrounds and professions. Marlo Lewis, an American environmental scholar and policy analyst, was born in 1964 and has made significant contributions to the field of environmental economics.