The name Kristin is a girl's name of German, Norwegian origin meaning "a Christian". Kristin and is often added to lists like International Variations of Christina and discussed in our forums with posts like "Generation CAF #59 (w/ occupations)".
From the experts:
A crystalline name that retains its loveliness far past its prime. Its biggest downside: Eternal confusion over spelling and pronunciation. Kristen? Kirsten? It can be so confusing that many parents today opt to bypass it.