Marni is a distinctive girls' name in England & Wales, ranking #1196 in 2007 with 23 recorded births. The name reached its all-time peak in 2014 with 48 births ranking #802. Since 1996, the popularity has increased by 283.3%. In 2007, approximately 1 in every 13,309 girls born was named Marni. FALLING Recent data shows the name is currently falling.