Sydnei is a distinctive girls' name in United States, ranking #4295 in 1999 with 27 recorded births. The name reached its all-time peak in 2005 with 37 births ranking #3936. Since 1996, the popularity has decreased by 20.6%. In 1999, approximately 1 in every 65,696 girls born was named Sydnei. RISING Recent data shows the name is currently rising.