Alasdair is a masculine given name of Scottish origin, derived from the Gaelic name Ailig, which means "defender of mankind." It is often Anglicized to Alexander but retains its unique Gaelic charm and meaning. The name Alasdair is composed of two elements: 'al' meaning noble or heroic, and 'asidh', meaning peace or tranquility. This combination suggests a balance between bravery and serenity. Historically, it has been used primarily in Scotland, but like many other Scottish names, it has gained international recognition and usage. Some notable individuals bearing this name include Alasdair Gray, a prominent Scottish writer, and Alasdair MacIntyre, a renowned philosopher.
The name Alasdair saw a significant increase in popularity from the late 90s to mid-2000s, with a notable spike in 2007 (19 births) and 2011 (23 births). However, it remains relatively uncommon overall, with total births reaching 467 since 1989.