Katja is a name of Slavic origin, derived from the Russian 'Yekaterina', which means 'pure' or 'clear'. It has been popularized in various forms across Europe, with notable variations including Katherine and Katarina. In many languages, Katja is used as a familiar form of these longer names. The name gained significant prominence during the Middle Ages, particularly among the Russian nobility, and has since become a timeless classic across different cultures.
The popularity of the name Katja has seen significant fluctuations over time. Between 1963 and 1980, there were consistently fewer than 15 births per year, with a peak of just 12 in 1979. However, starting from 1984, the number of girls named Katja began to rise steadily, reaching a high of 40 births in 1994. The name's popularity continued to fluctuate throughout the 1990s and early 2000s, with peaks around 35 births per year. In recent years, the number of newborn girls named Katja has declined again, with fewer than 20 births recorded each year since 2016. Overall, there have been a total of 935 births registered as Katja from 1963 to 2023.