Caillou is a distinctive boys' name in United States, ranking #6144 in 2009 with 14 recorded births. This places Caillou in the top 42% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2001 with 35 births ranking #2690. In 2009, approximately 1 in every 141,665 boys born was named Caillou. FALLING Recent data shows the name is currently falling.