Alethea is a distinctive girls' name in England & Wales, ranking #1649 in 2012 with 18 recorded births. The name reached its all-time peak in 2012 with 18 births ranking #1649. Since 1996, the popularity has increased by 260.0%. In 2012, approximately 1 in every 17,892 girls born was named Alethea. FALLING Recent data shows the name is currently falling.