Alastair is a distinctive boys' name in United States, ranking #4542 in 1999 with 15 recorded births. The name reached its all-time peak in 2025 with 67 births ranking #2147. Since 1996, the popularity has decreased by 11.8%. In 1999, approximately 1 in every 128,006 boys born was named Alastair. RISING Recent data shows the name is currently rising.