Chocolate milk has been around since the 17th century, when it was reportedly created by Hans Sloane in British Jamaica.
While the exact origins are somewhat debated, the widespread story attributes the creation of chocolate milk to Sir Hans Sloane, an Irish physician and collector. During his time in Jamaica in the late 1600s and early 1700s, he found the local cocoa drink to be unpalatable. He then mixed it with milk, making it more palatable.
Chocolate’s use with milk predates this period, as other sources trace chocolate beverages back even further, though not always specifically in the milk chocolate form we know today. However, Sloane is credited with popularizing the beverage in Europe.
Therefore, whether looking at initial invention or popularization, chocolate milk has existed for several centuries.