(February 4, 1806 – December 10, 1866) was a nineteenth-century American Presbyterian pastor, academic and theologian who served as president of Hanover College and Miami University.

Along with Henry Ward Beecher, McMaster was one of the most vocal Presbyterian anti-slavery advocates in Indiana.

His father was a Reformed Presbyterian minister who immigrated from Ireland in 1791.

He was licensed by the Northern Reformed Presbytery in 1829 and preached for one year for congregations with no ministers.

After joining the Presbyterian Church (USA) in 1830, he was ordained by its Albany Presbytery in 1831 and installed as the pastor of a congregation in Ballston, New York, from 1831, which he served until 1838, when he became the third president of Hanover College.