Isobelle is a moderately popular girls' name in England & Wales, ranking #414 in 2001 with 74 recorded births. The name reached its all-time peak in 2009 with 181 births ranking #265. Since 1996, the popularity has increased by 68.2%. In 2001, approximately 1 in every 3,621 girls born was named Isobelle. FALLING Recent data shows the name is currently falling.