Alastair McDonald, or variants, may refer to:
After 1900 Alistair MacDonald (born 1970), British judge Alistair Macdonald (1925–1999), British Labour party politician Alastair Macdonald (surveyor) (born 1932), British land surveyor and author Alastair Macdonald (historian), Scottish historian Alastair McDonald (musician) (born 1941), Scottish banjo-playing folk/jazz musician Alisdair Macdonald (1940–2007), British press photographer
Pre-20th century Alastair Macdonald (British Army officer), 19th century Commander-in-Chief, Scotland Alasdair Mac Colla (died 1647), 17th century Scottish military officer Alexander of Islay, Earl of Ross (died 1449), also known as Alasdair MacDonald, 15th century Scottish nobleman Alistair Carragh Macdonald, 15th century Scottish nobleman Alasdair Óg of Islay (died 1299), known as Alasdair MacDonald, 13th century Scottish Lord of Islay and chief of Clann Domhnaill Alasdair Mór, 13th century Scottish nobleman and eponymous ancestor of Clan MacAlister