Given name
Alasdair
“helper and defender of mankind”
In Scottish Gaelic use, Alasdair has a related form in Alastair. In Scottish use, Alastair carries the interpretation “helper and defender of mankind.”
Meaning & origin
What it means
In Scottish Gaelic use, Alasdair has a related form in Alastair. In Scottish use, Alastair carries the interpretation “helper and defender of mankind.”
Explained through its name family
Where it comes from
Alasdair is a form of Alexander. Alexander has been associated with Latin and Greek naming traditions.
Explained through its name family
How it developed
In Scottish Gaelic usage, Alasdair developed from Alexander. In Scottish Gaelic usage, Alasdair developed from Ἀλέξανδρος.
The story
Published U.S. birth records include this spelling as early as 1989. This is the earliest published observation available here, rather than a date for the name’s origin.
From dated birth records
Alasdair through the years
- Babies since 1880
- 525
- 525 boys · 0 girls
- Most popular year
- 2021
- 37 babies
- 2025
- 28
- #3,850 for boys
- 2021–25 vs 2016–20
- +38%
- Rising
By the numbers
In 2025, this name appeared in 28 U.S. birth records for boys, ranking No. 3,850 among boys’ names. Average annual use for boys was 37.7% higher in 2021–2025 than in 2016–2020. Published U.S. population figures for this spelling include 538 as a first name in 2020.
From Social Security birth records and U.S. Census name counts for this exact spelling. Other spellings are counted separately.
Alasdair’s family of names
In English usage, Alasdair has a diminutive in Sandy. In Scottish Gaelic usage, Alasdair developed from the Latin form Alexander. In Scots usage, Alasdair has a conventional equivalent in the Spanish form Alejandro.
Inner ring: nicknames and forms · outer: across languages.
Around the world
Alasdair has relatives in 11 languages.
18 related names in 11 languages. Point at a dot, or tab to the map and use the arrow keys.
Nicknames & forms 8
Diminutives, pet forms, short forms and variants used alongside the name.
Across languages 12
Equivalents and cognates in other languages, plus older forms it grew from.
People named Alasdair
- Alasdair MacIntyreScottish-American philosopher (1929–2025)
- Alasdair GrayScottish writer and artist (1934–2019)
- Alasdair Mac CollaScottish knight1610–1647
- Alasdair mac Mhaighstir AlasdairBritish poet, lexicographer, political writer and memoirist1698–1770
- Alasdair StrokoschScottish rugby union playerborn 1983
- Alasdair McDonnellIrish politicianborn 1949
- Alasdair FraserScottish fiddlerborn 1955
- Alasdair Milneformer Director-General of the British Broadcasting Corporation1930–2013
- Alasdair EvansScottish cricketer (born 1989)
Listed by how widely each person is written about, which says nothing about the name itself.
Appears in
Similar names
If you love Alasdair, these share its style, era, origin or sound, from outside its own family.