Slavic and Russian name, possibly derived from a word meaning "strong water" or a feminine form of Ina.
Inna is a feminine name with ancient roots in the early Christian world of Eastern Europe and the Caucasus. It is closely associated with the martyr Saint Inna, one of three disciples — Inna, Pinna, and Rimma — who according to tradition were baptized by the Apostle Andrew during his missions through Scythia (roughly modern Ukraine and southern Russia). The three were reportedly martyred by pagan Scythians around the first or second century CE, drowned through holes cut in river ice, and they are venerated in Eastern Orthodox and Eastern Catholic traditions on February 2nd (January 20th in the Old Calendar).
This gives the name a remarkable antiquity as a Christian name in the Slavic and Eastern European world. The etymology of Inna is not entirely settled. Some scholars link it to the Latin 'innocens' (innocent), while others suggest a Greek origin or even a pre-Christian Scythian or Iranian root.
What is clear is that as the name moved through Slavic cultures it accumulated warmth and familiarity, becoming a beloved given name across Russia, Ukraine, Belarus, and Bulgaria. In twentieth-century Russia it was consistently popular, carrying a clean, modern sound that belied its patristic origins. Innna carries a certain elegant brevity — two syllables, open vowels, a name that sits quietly without demanding attention.
Outside the Slavic world it remains genuinely uncommon, which gives it an air of discovery for parents in English-speaking countries. Its similarity to familiar names like Anna and Nina makes it phonetically accessible while its doubled 'n' and its history give it a depth that purely invented names cannot claim.