Although several tales exist as to why Rosehearty received its name, it is most likely they are but stories. In fact the more realistic source of the name is from the Gaelic "Ross'; meaning a promontory and "ard" a height. However, Pratt suggests it may also be from Rossachdair, "the anchorage ground near the promontory".

The name Pitsligo is of Pictish origin as are the nearby Pittulie and Pittendrum.