Sir Ian MacGregor (1912–1998) was a Scottish-American metallurgist and industrialist
Ian MacGregor, Macgregor or McGregor may also refer to:
Ian McGregor (malariologist) (1922–2007) Ian McGregor (Australian footballer) (born 1942), Australian rules footballer Ian McGregor (Scottish footballer) (born 1953) Ian Macgregor (born c. 1937), British investment executive and chartered accountant Ian MacGregor (journalist), British newspaper editor Ian MacGregor (cyclist) (born 1983), American professional road racing Ian MacGregor (rugby union) (1931–2016), Scottish rugby union player