Hiram McCullough (September 26, 1813 – March 4, 1885) was a U.S. Congressman from Maryland who served two terms from 1865 to 1869. McCullough served in the Maryland Senate from 1845 to 1851. He also served in the Maryland House of Delegates from 1880 to 1881 and served as the Speaker of the Maryland House of Delegates in 1880.