Charlotte Matilda Hughes MacLeod was born in Bath, New Brunswick, Canada, on November 12, 1922, the daughter of Edward Philips MacLeod and Mabel Maude Hayward MacLeod. During her childhood, her family moved to the United States, and she attended public schools in Weymouth, Massachusetts. She then attended the School of Practical Art in Boston (now the Art Institute of Boston).
MacLeod began her professional career in advertising in 1952, working for N. H. Miller in Boston, where she remained until 1982. She worked as copy chief and eventually became a vice president in the firm. While working in Boston, MacLeod resided on Beacon Hill and later in Sudbury, a small town west of Boston. There, she was a member and officer of the Sudbury Garden Club. After leaving N. H. Miller, MacLeod moved to Maine.
By the age of ten, MacLeod had decided that she would write mysteries for young readers because she could not find enough of them to read. MacLeod first began publishing fiction and articles in popular magazines in the 1960’s. Her early fiction was written primarily for teenagers, and many of these works are mysteries. One of her juvenile mysteries, We Dare Not Go A-Hunting, published in 1980, was nominated for an Edgar Allan Poe Award by the Mystery Writers of America.
MacLeod began writing her better-known mystery fiction for adult readers in the late 1970’s and quickly attracted a reading audience that enjoyed her “witty and literate” style. In addition to writing, she did illustrations and paintings. MacLeod died on January 14, 2005, at the age of eighty-two in Lewiston, Maine.