Alethea is a distinctive girls' name in England & Wales, ranking #1865 in 2015 with 15 recorded births. The name reached its all-time peak in 2012 with 18 births ranking #1649. Since 1996, the popularity has increased by 200.0%. In 2015, approximately 1 in every 20,528 girls born was named Alethea. FALLING Recent data shows the name is currently falling.