Thaddius is a distinctive boys' name in United States, ranking #6928 in 2004 with 11 recorded births. The name reached its all-time peak in 2001 with 12 births ranking #5975. Since 1996, the popularity has increased by 83.3%. In 2004, approximately 1 in every 180,437 boys born was named Thaddius. FALLING Recent data shows the name is currently falling.