'Morello' originates from Italian, specifically the word 'morello', a diminutive or derivative of 'moro' meaning 'dark' or 'swarthy' (ultimately from Latin 'maurus').

'Morello' came into English as the name of a cherry variety via Italian and possibly French usage; Italian 'morello' derives from Vulgar Latin *maur-ellus < Latin 'maurus' meaning 'dark, Moor'. The word was adopted into English horticultural vocabulary by the 17th–18th century to denote the dark sour cherry.

Initially it meant 'dark' or 'dark-colored' (applied descriptively); over time it became a fixed name for a specific variety of sour cherry and also appears as a surname.