Isaac Erb Bowman (August 17, 1832 – September 3, 1897) was an Ontario businessman and political figure. He represented Waterloo North in the Canadian House of Commons as a Liberal member from 1867 to 1878 and from 1887 to 1896.
He was born Isaac Erb Baumann in Woolwich Township in Upper Canada in 1832, the son of John B. Bowman; his parents had come there from Pennsylvania in 1820. He attended school at the Rockwood Academy in Rockwood, Ontario. For a time, he taught school in the region. Bowman was a partner in a business that sold books in Berlin (later Kitchener, Ontario) and in a tannery in St. Jacobs. He served as clerk and treasurer for the township and was also postmaster for St. Jacobs. He served as president of the Ontario Mutual Life Insurance Company and the Mercantile Fire Insurance Company. He was elected to the Legislative Assembly of the Province of Canada in an 1864 by-election for the North riding of Waterloo and he was acclaimed in the same riding after Confederation. He was defeated by Hugo Kranz when he ran for reelection in 1878; Bowman defeated Kranz to win the seat in 1887 and 1891.
Bowman married Lydia Bowman. His son Charles Martin later became a member of the Ontario provincial assembly.