Thadius is a distinctive boys' name in United States, ranking #5255 in 1997 with 12 recorded births. The name reached its all-time peak in 1998 with 14 births ranking #4847. Since 1996, the popularity has increased by 20.0%. In 1997, approximately 1 in every 157,091 boys born was named Thadius. RISING Recent data shows the name is currently rising.