William Grant Laidlaw (January 1, 1840 – August 19, 1908) was a U.S. Representative from New York. Born near Jedburgh, Roxburghshire, Scotland, Laidlaw immigrated to the United States in 1852 with his parents, who settled in Franklinville, New York. He attended the common schools and Ten Broeck Free Academy in Franklinville. He studied law, was admitted to the bar in 1866 and practiced. Laidlaw served two years in the United States Navy during the Civil War. He was School Commissioner of the Cattaraugus County first district from 1867 to 1870.