Koi is a distinctive girls' name in United States, ranking #2619 in 2021 with 66 recorded births. This places Koi in the top 15% of ranked US girls' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2025 with 84 births ranking #2207. In 2021, approximately 1 in every 24,844 girls born was named Koi. RISING Recent data shows the name is currently rising.