Alethea has been given to about 4,968 people in the United States since 1880. It was most common in 1973, which makes it a boomer-era name.
Its best year was 1973, when 322 babies were given the name, ranking 522nd. The typical living American called Alethea is about 50 years old today. It is relatively most common in New York, where it accounts for 0.00% of births.
Source: US Social Security Administration, national and state name files, 2025 release, and the Office for National Statistics for England and Wales. Etymology researched and written by our editors. Living-population and median-age figures are our own estimates, described in the methodology.