Horace Lyman (November 16, 1815 – March 31, 1887) was a reverend and professor of mathematics in the U.S. state of Oregon. He was born in Massachusetts, and came to Oregon by way of New York and Cape Horn in October 1848. He married Mary Dennison the next month. He established a school in Portland in 1849, and helped establish the Hillsboro School District in Hillsboro in 1851. He was a founder of Portland's First Congregational Church in June 1851. He was founding secretary of LaCreole Academic Institutue near Dallas, Oregon in 1856.