Marni is a distinctive girls' name in England & Wales, ranking #1594 in 2000 with 11 recorded births. The name reached its all-time peak in 2014 with 48 births ranking #802. Since 1996, the popularity has increased by 83.3%. In 2000, approximately 1 in every 24,834 girls born was named Marni. FALLING Recent data shows the name is currently falling.