Rye Country Day School traces its beginnings to 1869, when a group of local parents, wishing to improve the quality of education available for their daughters, contacted The Rev. William Life and his wife, Susan, who ran a small school in Pennsylvania. The Lifes came to Rye and established The Rye Female Seminary under the direction of Mrs. Life. During its first year, 60 students (25 boarders and 35 day students) enrolled in the seminary, which was located on the present school property on Grandview Avenue.

The year 1921 saw the seminary merge with a boys' school from nearby Harrison — The Rye Country School — and became known as The Rye Country Day Schools. The "s" was later dropped from the word "Schools."

RCDS enrolls students from preschool through 12th grade.