John Howard Nichols was born in 1838, in Kingston, New Hampshire, to Nicholas and Mary Jewett (Barstow) Nichols. He grew up in Exeter, New Hampshire, where he attended Phillips Academy. After graduation, he taught at a school in Stratham, New Hampshire for a year, before moving to Boston to work as a clerk for a tea importing house on Central Wharf. It was there that Nichols was noticed by John L. Gardner, who hired him as a supercargo on the bark Arthur, which was bound for China in 1858. Once he arrived in China, Gardner requested that Nichols remain in China to act as an agent. He accepted the position and remained in China for ten years, returning to America once during this time (Foster 337).

Upon returning to America in 1868, he imported Japanese and Chinese teas, until he took the position of treasurer for the Boston, Massachusetts textile firm Dwight Manufacturing Company, in 1876. Under Nichols' management, Dwight Manufacturing "became one of the most profitable textile [factories] in New England" (Foster 338). Nichols later established a branch cotton mill in Alabama City, Alabama, which added to the company's earnings. In 1905, Nichols became president of the company, a position he held until his death. He also served as treasurer of the Great Falls Manufacturing Company, and as president of Lyman Mills and Manchester Mills (Foster 338).

On March 15, 1870, Nichols married Charlotte Peabody Kimball, the daughter of Daniel B. and Charlotte C. Kimball, in Bradford, Massachusetts. The couple had four children: Howard Gardner, Eleanor Marcey, Grace, and Charlotte Greene. He died in Newton, Massachusetts, at the age of 67 on September 15, 1905.