John Farnham Boynton (September 20, 1811 – October 20, 1890) was an early leader in the Latter Day Saint movement and an American geologist and inventor.

Boynton was baptized a member of the Church of Jesus Christ of Latter Day Saints by Joseph Smith in September 1832 in Kirtland, Ohio.

In May 1837, U.S. President Andrew Jackson ordered the U.S. Treasury to accept only gold for public land, rejecting privately printed paper money such as the Safety Society and other unchartered community institutions produced.

However, the dissenters, led by Boynton, Warren Parrish, Martin Harris, and Luke Johnson, had a strong local following and took physical control of the Kirtland Temple, the major financial asset of the church.

They also sought to control the church organization and led a competing high council which excommunicated Smith and Rigdon, who left the city and fled to Far West, Missouri.

In 1838, after Smith had relocated to Missouri, Boynton and other dissident church leaders, including Oliver Cowdery, David Whitmer, and the Johnsons, were excommunicated.

His nephew (son of his sister, Olive Boynton Hale), Alma Helaman Hale, of Grantsville, Utah Territory, reported that Boynton visited Brigham Young (also one of the original members of the Quorum of the Twelve) during a visit to Utah Territory and counseled Erastus Snow to continue his efforts and involvement with the church.

Boynton declared that the giant could not be a fossilized man, but hypothesized that it was a statue that was carved by a French Jesuit in the 16th or 17th century in order to impress the local Native Americans.