Joslyn is a distinctive girls' name in United States, ranking #637 in 2011 with 448 recorded births. The name reached its all-time peak in 2010 with 461 births ranking #641. Since 1996, the popularity has increased by 130.9%. In 2011, approximately 1 in every 3,926 girls born was named Joslyn. FALLING Recent data shows the name is currently falling.