Kavaliou is a Belarusian surname, an alternate transcription of the Cyrillic Кавалёў (see Kavalyow). The name is a patronymic derived from the Belarusian word каваль (kaval'), meaning "blacksmith," making it cognate with surnames such as English Smith or other Slavic occupational names like Kovač (Slovene), Kovac (Slovak), Kovachev (Bulgarian), and Kovačević (Serbian).
Occupational surnames were widely adopted throughout Europe during the Middle Ages. In the East Slavic lands, the -іў (-yow) suffix originated as a patronymic ending, thus a name like Kavaliou originally referred to a descendant of a blacksmith. The alternation between forms such as Kavaliou and Kavalyow reflects variations in the Latin transcription of the Belarusian Cyrillic alphabet under different linguistic standards (e.g., Taraskievica vs. the official norm used after independence).
While specific bearer information is not provided, similar Belarusian surnames are common across the country, particularly in rural regions where smithing was a prominent trade. The feminine form of the name is Kavalìova (or Kavalyova), following Belarusian grammar. The root name Kavalyow also yields the masculine patronymic Kavalchuk (likely a diminutive), as seen in the related masculine forms.