Isobelle is a moderately popular girls' name in England & Wales, ranking #303 in 2010 with 156 recorded births. The name reached its all-time peak in 2009 with 181 births ranking #265. Since 1996, the popularity has increased by 254.5%. In 2010, approximately 1 in every 2,058 girls born was named Isobelle. FALLING Recent data shows the name is currently falling.