Sidney is a moderately popular girls' name in United States, ranking #337 in 1996 with 828 recorded births. The name reached its all-time peak in 2000 with 1,221 births ranking #265. In 1996, approximately 1 in every 2,117 girls born was named Sidney. FALLING Recent data shows the name is currently falling.
Sidney is an English surname name that later moved into first-name use. Its modern identity comes more from that surname history than from a single neat word meaning.
Behind the Name says it first became a given name in honour of Algernon Sidney, and later usage was shaped by other notable bearers of the surname. In the United States it also shifted across gender lines over time.