Marni is a distinctive girls' name in England & Wales, ranking #1045 in 2005 with 24 recorded births. The name reached its all-time peak in 2014 with 48 births ranking #802. Since 1996, the popularity has increased by 300.0%. In 2005, approximately 1 in every 12,011 girls born was named Marni. FALLING Recent data shows the name is currently falling.