Alastair is a distinctive boys' name in United States, ranking #5146 in 2001 with 14 recorded births. The name reached its all-time peak in 2025 with 67 births ranking #2147. Since 1996, the popularity has decreased by 17.6%. In 2001, approximately 1 in every 138,774 boys born was named Alastair. RISING Recent data shows the name is currently rising.