Donald R. Grant was born in Montclair, New Jersey, on April 20, 1923. He entered Amherst College in the fall of 1941, but left in 1943 to enlist in the United States Navy. He served in the Pacific during World War II and was discharged with the rank of lieutenant in 1946. He returned to Amherst and graduated in 1947. Justice Grant then attended Harvard Law School, from which he graduated with honors in 1950. After clerking for a year for Supreme Judicial Court Justice John Varnum Spalding, he joined the Boston law firm of Ropes & Gray in the fall of 1951. He became a partner in the firm in 1961, specializing in appellate work and municipal law. He argued eighteen cases before the Supreme Judicial Court and wrote briefs, in whole or in part, in thirty cases.
In 1972, Governor Frank Sargent appointed him as one of the first six justices of the newly created Appeals Court. During the next sixteen years he wrote more than 1,100 decisions, including more than 200 signed opinions and 300 rescript opinions. As one of the Court's original members, he played a major role in drafting its rules and in establishing many of its internal operating procedures. Justice Grant retired from the Appeals Court in 1988 at the age of sixty-five. A longtime resident of Lexington, and later of Concord, he spent much of his time during retirement at his home in Wolfeboro, New Hampshire. He died there on March 28, 2007. Justice Grant was married first to Ruth Chadwick, who predeceased him. They were the parents of a daughter. Justice Grant later married Abigail Fletcher.
The Appeals Court's Memorial to Justice Grant may be found at 71 Mass. App. Ct. 1129 (2008).