Joslyn is a distinctive girls' name in United States, ranking #729 in 2005 with 372 recorded births. The name reached its all-time peak in 2010 with 461 births ranking #641. Since 1996, the popularity has increased by 91.8%. In 2005, approximately 1 in every 4,967 girls born was named Joslyn. FALLING Recent data shows the name is currently falling.