Cynthia is a moderately popular girls' name in United States, ranking #381 in 2010 with 835 recorded births. The name reached its all-time peak in 1996 with 3,189 births ranking #101. Since 1996, the popularity has decreased by 73.8%. In 2010, approximately 1 in every 2,129 girls born was named Cynthia. FALLING Recent data shows the name is currently falling.