'Tonya' originates from Russian/Slavic influence, specifically as an English respelling or variant of the Russian diminutive 'Tanya' (Таня), which itself is a diminutive of the name 'Tatiana'.

'Tonya' changed from the Russian diminutive 'Tanya' (from 'Tatiana') and eventually became used in English-speaking contexts as the modern name 'Tonya'. 'Tatiana' ultimately derives from the Roman family name 'Tatius'.

Initially used as a diminutive meaning 'little Tatiana' or 'daughter of Tatiana', it has evolved into an independent female given name 'Tonya' in modern usage.