Marni is a distinctive girls' name in England & Wales, ranking #1056 in 2003 with 22 recorded births. The name reached its all-time peak in 2014 with 48 births ranking #802. Since 1996, the popularity has increased by 266.7%. In 2003, approximately 1 in every 12,667 girls born was named Marni. FALLING Recent data shows the name is currently falling.