Darnton is an English surname. Therefore, the most likely origins are either (1) related to some place (2) related to some occupation (3) perhaps indicative of some relationship. The word, and its components, Darn - ton, indicate that (2) and (3) are unlikely. Therefore, most ancestors are likely to come from the same place. The -ton at the end is one of the most common endings in English place names. Its meaning can be such as town, village, hamlet, farmstead, enclosure, fence or hedge. Several writers suggest this has become an enclosed village or farmstead.
https://en.wikipedia.org/wiki/Darnton