Sylvester Pennoyer (July 6, 1831 – May 30, 1902) was an American educator, attorney, and politician in Oregon. He was born in Groton, New York, attended Harvard Law School, and moved to Oregon at age 25. A Democrat, he served two terms as the eighth Governor of Oregon from 1886 to 1895. He joined the Populist cause in the early 1890s and became the second Populist Party state governor in history. He was noted for his political radicalism, his opposition to the conservative Bourbon Democracy of President Grover Cleveland, his support for labor unions, and his opposition to the Chinese in Oregon. He was also noted for his prickly attitude toward both U.S. Presidents whose terms overlapped his own -- Benjamin Harrison and Cleveland, whom he once famously told via telegram to mind his own business.