Alastair is a distinctive boys' name in United States, ranking #2979 in 2020 with 39 recorded births. The name reached its all-time peak in 2025 with 67 births ranking #2147. Since 1996, the popularity has increased by 129.4%. In 2020, approximately 1 in every 44,232 boys born was named Alastair. RISING Recent data shows the name is currently rising.