Allegra is a distinctive girls' name in England & Wales, ranking #758 in 2010 with 48 recorded births. The name reached its all-time peak in 2018 with 63 births ranking #641. Since 1996, the popularity has increased by 433.3%. In 2010, approximately 1 in every 6,688 girls born was named Allegra. STABLE Recent data shows the name is currently stable.