MacInnes was educated at the Hamilton Academy. He spent most of his life managing station properties in Victoria and New South Wales, retiring to Melbourne in 1914 where he died two years later.
He was a fine horseman and sportsman, with a particular love of horses and dogs. He contributed articles to newspapers and journals and wrote a novel, Straight as a Line: An Australian Sporting Story. At the time of his death he had almost completed a second story of station life and sport. A selection of his poetry including poems previously published in the Sydney Mail, Town and Country, the Australasian and the Pastoral Review, was published posthumously.