William Metcalfe (March 11, 1788 –  October 16, 1862) was an English-American minister in the Bible Christian Church, homeopathic physician, and activist for vegetarianism, pacifism, temperance and abolitionism.

Despite the church's financial struggles, Metcalfe actively engaged in preaching, education, and publications addressing societal issues.

He played a pivotal role in founding the American Vegetarian Society in 1850 and succeeded William Alcott as its president in 1859.

Wright persuaded Metcalfe to study theology, leading him to an academy in Salford, presided over by William Cowherd, the founder of the Bible Christian Church.

[4] After establishing themselves in the United States, Metcalfe and his wife, endeavored to impart lessons on pacifism, temperance, abolitionism, and vegetarianism to their neighbors—core principles of their faith.

Occasionally, he encountered resistance and criticism for his stance on vegetarianism, with newspapers questioning his preaching and character, even labeling him as an "Infidel.

Beyond his preaching duties, he devoted his time to instructing in the church's modest school and authored and published two newspapers addressing topics like slavery, temperance, and presumably, vegetarianism.