Allegra is a distinctive girls' name in England & Wales, ranking #760 in 2015 with 51 recorded births. The name reached its all-time peak in 2018 with 63 births ranking #641. Since 1996, the popularity has increased by 466.7%. In 2015, approximately 1 in every 6,038 girls born was named Allegra. STABLE Recent data shows the name is currently stable.