Alethea is a distinctive girls' name in England & Wales, ranking #1475 in 2000 with 12 recorded births. The name reached its all-time peak in 2012 with 18 births ranking #1649. Since 1996, the popularity has increased by 140.0%. In 2000, approximately 1 in every 22,765 girls born was named Alethea. FALLING Recent data shows the name is currently falling.