Koi is a distinctive girls' name in United States, ranking #4123 in 2020 with 34 recorded births. This places Koi in the top 24% 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 2020, approximately 1 in every 47,515 girls born was named Koi. RISING Recent data shows the name is currently rising.