In September 1923, Sir Gilbert and Lady Eliott, and Miss Adelaide Vincent Smith with the help of Miss Nellora Reeder and Mrs. Barbara Templin, founded the K-7th grade Harbor School at 59 Bayview Avenue in Port Washington. Sir Gilbert Eliott financed the school with the purpose of guaranteeing a private school education for his children until they returned to England.
In 1924, since a public school in Port Washington already bore the Harbor School name, Sir Gilbert Eliott suggested changing the name to the the Vincent Smith School, in honor of Miss Smith as the Principal and cofounder. The school was also moving to a new home at 25 Main Street for the 1924-1925 school year, as Bayview Ave. was only zoned for residential use. With an 8th grade added in 1926, the school quickly began to outgrow its Main St. home. In 1927 Sir Gilbert and Lady Eliott purchased part of the Lapham Estate at 322 Port Washington Boulevard and built the original, yellow two-story building, which now houses the Lower School.
After its inception, the Vincent Smith School catered almost exclusively to the children of the affluent from Long Island's North Shore. The first class of the school included the children of Christopher Morley, LeRoy Grumman, William A. Shea, Harry F. Guggenheim, the Loukenbachs and many others. In 1931, the first ninth grade certificate went to Christopher Morley, Jr., who became a minister in Chattanooga, Tennessee. The second certificate went to Ann Willets Lapham, the daughter of one of the foremost Quaker families on Long Island.
The School operated on a provisional charter, granted on June 11, 1931 by the New York State Board of Regents. This provisional charter incorporated the school with Gilbert Eliott, Dora F. Eliott, Edward M. Lapham, Edward M. Lapham, Jr. and Adelaide V. Smith as the executive officers. Sir Eliott died in 1926, and his son, Gilbert Eliott, continued financial support of the school. When the stock market crashed in 1929, financial support of the school was withdrawn and the Eliotts returned to Scotland. The 1930's and 1940's were lean years for Vincent Smith. Teachers and parents made sacrifices to help the school.
On July 20, 1951, an absolute charter was granted by the Board of Regents of the State of New York. In 1952, the gymnasium was added to the Lower School. Over the years, the reputation of the school grew, and this success necessitated the acquisition of a new building, which now houses the Middle School. This structure was a private home built in 1962 for William Schluntz, son-in-law of Edward Lapham. It was purchased in 1963 and converted to the present day structure.
In the summer of 1970, dwindling resources and rising inflation threatened to end the school's existence, but determined, strongly committed parents raised funding to save the School. In 1974, this enthusiasm resulted in a decision to construct a new building in order to accommodate the growing student body and the expansion of the School to include a 10th, 11th, and 12th grade. The first High School Senior Class was graduated in June, 1974. The Board of Regents registered (accredited) the school on September 25, 1980. In 1988, four classrooms were added to the west end of the High School. In 1989, Vincent Smith School was proud to receive accreditation from the New York State Association of Independent Schools. That accreditation was renewed by NYSAIS in August, 2000 and once again in June, 2010.

Timeline
- 1923 - Harbor School Founded
- 1924 - Name Changed to Vincent Smith School
- 1927 - Lower School Built on Current Campus
- 1931 - First 9th Grade Certificate Conferred
- 1931 - Provisional Charter Granted by NYS Board of Regents
- 1951 - Absolute Charter Granted by NYS Board of Regents
- 1952 - Gymnasium Added to Lower School
- 1962 - Growth Required Acquisition of the Middle School
- 1974 - High School Building was Constructed
- 1974 - First High School Senior Class Graduated
- 1980 - School Received Accreditation from NYS Board of Regents
- 1988 - High School Expansion
- 1989 - School Received Accreditation from NYS Association of Independent Schools (NYSAIS)
- 2000 - NYSAIS Renews Accreditation
- 2009 - Vincent Smith School celebrates its 85th Anniversary
- 2010 - NYSAIS Renews Accreditation
- 2014 - John Baldi becomes new Head of School
- 2015 - School expands to includes grades 1, 2 and 3
- 2016 - School adds VEEP (Vocational Explorations and Education Program)
- 2022 - Vincent Smith General Store opens at 189 Main St., an extension program of VEEP