In 1967, a group of Wilson, North Carolina parents assembled and discussed the prospect of opening a new independent school in Wilson. Forty students, representing twenty-nine families, were enrolled at Greenfield Academy in the fall of 1969, with its first Headmaster John Hughes.
Within the next two years, Greenfield Academy became a kindergarten through grade twelve school, and in June 1972 the school hired its second Headmaster, Dr. George H. Bell.
During the early years of Dr. Bell's eleven-year tenure, Greenfield Academy changed its name to Greenfield School. In 1973, the first class of seniors graduated. A new library was built in 1973, and a gymnasium was constructed in 1974. In May 1975, Greenfield was accredited by the Southern Association of Colleges and Schools. During the next eight years, enrollment climbed to 300 students. Tennis courts and soccer fields were added, and the school gained local and state acclaim for its strong academics and accomplished soccer teams. Dr. Bell resigned in 1983, and Jeffrey Thompson became Greenfield's third Headmaster. During the next four years, a preschool program was added.
In 1987, Mr. Thompson resigned, and Mrs. Janet Beaman, a teacher at Greenfield School for fifteen years and Assistant Headmaster for nine years, was appointed as Greenfield's fourth Headmaster. Greenfield School opened that fall with an expanded preschool that included a program designed for two-year-olds. Greenfield School became a school, which values the continuation of education spanning sixteen years in the life of a child.
During the 1995-96 school year, through the generosity of the family and friends of Greenfield, major campus renovations were completed, including the Skinner Technology Center, which houses four science labs and three computer labs.
The 2010-11 school year marked several major milestones in the history of the school. Janet Beaman, after twenty-four years as Headmaster and thirty-nine total years of service to Greenfield, retired at the end of the school year. After a nationwide search, Dr. Vincent Janney, formerly of The Peck School in Morristown, New Jersey, was unanimously voted by the Board of Trustees to become the school's next headmaster. In addition, Greenfield School acquired an additional 41 acres adjacent to the existing property for future expansion.
The 2012-13 school year brought about the building completion of a new cafeteria, which is the first new building on campus since 1996.