Allegra is a distinctive girls' name in England & Wales, ranking #641 in 2018 with 63 recorded births. The name reached its all-time peak in 2018 with 63 births ranking #641. Since 1996, the popularity has increased by 600.0%. In 2018, approximately 1 in every 4,576 girls born was named Allegra. STABLE Recent data shows the name is currently stable.