Alexander McKenzie Ross (25 December 1805 – 8 August 1862) was a British builder and engineer.
Together with Robert Stephenson, son of the builder of the Rocket locomotive, he designed the famous Victoria Bridge at Montreal, Quebec, the first bridge to span the St. Lawrence River. The bridge, opened in 1859, remains in use to this day, carrying both road and rail traffic.
Ross was chief engineer for Canada's Grand Trunk Railway, including the Victoria Bridge over the St. Lawrence River.
He had been the former resident engineer on the Chester and Holyhead Railway, also working with Stephenson. They had worked on numerous challenging projects in the UK, together with Francis Thompson.
Ross died in Chiswick and is buried in Brompton Cemetery, London.