Alastair is a distinctive boys' name in United States, ranking #5850 in 1998 with 10 recorded births. The name reached its all-time peak in 2025 with 67 births ranking #2147. Since 1996, the popularity has decreased by 41.2%. In 1998, approximately 1 in every 191,132 boys born was named Alastair. RISING Recent data shows the name is currently rising.