Isaiah Mawhinney (12 December 1830 - 26 January 1913) was an Irish-born political figure in Manitoba. He represented Burnside from 1883 to 1886 in the Legislative Assembly of Manitoba as a Conservative.
He was born in County Monaghan and was educated there. In 1850, he married Elizabeth Rutledge. Mawhinney came to Manitoba in 1873.[1] In 1885, he was elected Provincial Grand Master for the Orange Order. Mawhinney was defeated by Kenneth McKenzie when he ran for reelection in 1886.[2] He died at Victoria, British Columbia in 1913.[2]