Thadius is a distinctive boys' name in United States, ranking #11989 in 2019 with 6 recorded births. The name reached its all-time peak in 1998 with 14 births ranking #4847. Since 1996, the popularity has decreased by 40.0%. In 2019, approximately 1 in every 298,894 boys born was named Thadius. RISING Recent data shows the name is currently rising.