Aleister is a variant of Alistair, the anglicized form of the Scottish Gaelic Alasdair, which is Alexander and means "defender of men". The spelling with ei was adopted by the British occultist Aleister Crowley, which gives it a slightly gothic flavor. In the United States Aleister stood at number 6852 in 2000, rose to its best rank of 2046 in 2020 and sits at number 2943 in 2025.