While there's no specific record of the first person to observe lunar craters, it's widely believed that Galileo Galilei was the first to document them in detail.

In 1609, Galileo used his improved telescope to observe the moon and meticulously sketched its surface. His drawings revealed numerous craters, mountains, and other features, which he described in his book "Sidereus Nuncius" (Starry Messenger).

Although others might have observed the moon's surface before Galileo, his detailed observations and documentation played a crucial role in understanding the moon's topography and its implications for our understanding of the solar system.