Marni is a distinctive girls' name in England & Wales, ranking #975 in 2016 with 37 recorded births. The name reached its all-time peak in 2014 with 48 births ranking #802. Since 1996, the popularity has increased by 516.7%. In 2016, approximately 1 in every 8,301 girls born was named Marni. FALLING Recent data shows the name is currently falling.