The history of St. Mark's begins on February 13, 1895, when a meeting was held in the Forge Village section of Westford to form a "General Committee to Secure Services of the Episcopal Church." For the next eight years, under the encouragement and direction of our mother church, St. Andrew's in Ayer, services were held in a recreation hall owned by the Abbot Worsted Company.

In 1898, the Parish of Ayer, Groton, Groton School and Forge Village was formed under the leadership of Dr. Endicott Peabody, founder and headmaster of the Groton School. Dr. Peabody assumed rectorship of the new parish. Assisting him was the Rev. Thomas Fisher, Vicar of the parish of St. Andrew's, Ayer. For the next ten years, Mr. Fisher worked to assure the firm establishment of the Forge Village mission. It was during his tenure that the mission building was constructed. In 1947, the direct overseeing of the parish by the Groton School headmasters ended and the institution of a full-time rectorship began. Church folklore tells us that Franklin Delano Roosevelt taught Sunday school in Forge Village while he was a student at the Groton School.

A vicarage on Pleasant Street was donated to the church by Mr. Dyson, who had bought the Abbot Worsted Mills. By late 1960, the Vestry of the United Parish raised the question of a separate church in Forge Village, distinct from St. Andrew's, Ayer. On April 25, 1961, on the Feast of St. Mark, St. Mark's Mission of the Diocese of Massachusetts came into being, continuing the history and congregation of the Forge Village Mission.

New facilites were needed and the diocese purchased five acres of land at the corner of Cold Spring and Graniteville Roads. In 1963, ground was broken for the new church. The move to a more central location in Westford was completed with the dedication on December 15,1964 of the present church and parish hall.