Alister George McLellan (4 June 1919 – 1 July 2012) was a New Zealand mathematician and physicist.
Born in Christchurch and brought up in Westport, McLellan attended Nelson College and then the University of Otago, from where he graduated with a BSc and an MSc in mathematics and science.
His thesis was entitled The radial distribution function and its application to the properties of fluids.
He was made a Fellow of the Royal Society of New Zealand in 1961 and Nuffield Foundation Commonwealth Bursary.
He served as president of the Canterbury Branch of the Royal Society of New Zealand.