Robert Adam Lyon (baptized 4 October 1829 – June 6, 1901) was a Canadian businessman and Liberal member of the Ontario Provincial Parliament from 1878 to 1884 and from 1885 to 1890.
He was born in Glasgow, Scotland in 1829 and came to Halton County, Ontario in Upper Canada with his parents in 1832.
With his brother William Durie Lyon, he opened a general store in Milton.
In 1878, he became the MLA for Algoma in a by-election, replacing Simon James Dawson.
This article about an Ontario Liberal Party MPP is a stub.