Marni is a distinctive girls' name in England & Wales, ranking #1013 in 2018 with 35 recorded births. The name reached its all-time peak in 2014 with 48 births ranking #802. Since 1996, the popularity has increased by 483.3%. In 2018, approximately 1 in every 8,236 girls born was named Marni. FALLING Recent data shows the name is currently falling.