Garreth is a distinctive boys' name in United States, ranking #5787 in 1997 with 10 recorded births. This places Garreth in the bottom 46% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 1998 with 18 births ranking #3900. In 1997, approximately 1 in every 188,509 boys born was named Garreth. FALLING Recent data shows the name is currently falling.