A significant portion of the neighborhood lies within the Upper East Side Historic District designated by the New York Landmarks Preservation Commission in 2013 and expanded in 2010. The neighborhood is part of Manhattan Community Board 8.
Based on the location of the original Lenox Hill, which was on a farm that spanned present-day 68th Street to 74th Street, east of Fifth Avenue, The Encyclopedia of New York City defines the neighborhood as the area between 60th Street and 77th Street, from Fifth Avenue on the west to Lexington Avenue on the east. However, neighborhood boundaries can shift and most residents see the modern boundaries differently, as the Lenox Hill post office and the neighborhood's service-oriented retail shops are located east of Lexington Avenue. Many maps also place Lenox Hill in the eastern section of the Upper East Side's lower portion, including maps of Manhattan Community District 8 and by the Friends of the Upper East Side.
The neighborhood is named for the hill that "stood at what became 70th Street and Park Avenue." The name "Lenox" is that of the immigrant Scottish merchant Robert Lenox (1759-1839), who owned about 30 acres (120,000 m2) of land "at the five-mile (8 km) stone", reaching from Fifth to Fourth (now Park) Avenues and from East 74th to 68th Streets. For the sum of $6,420 ($105,000 in current dollar terms) or $6,920 ($113,000) he had purchased a first set of three parcels in 1818, at an auction held at the Tontine Coffee House of mortgaged premises of Archibald Gracie, in order to protect Gracie's heirs from foreclosure, as he was executor of Gracie's estate. Several months later he purchased three further parcels, extending his property north to 74th Street. According to one source, "Thereafter these two tracts were known as the 'Lenox Farm.'" The tenant farmhouse stood on the rise of ground between Fifth and Madison avenues and 70th and 71st Streets, which would have been the hill, if the property had ever been called "Lenox Hill." The railroad right-of-way of the New York & Harlem Railroad passed along the east boundary of the property.
Robert Lenox's son James Lenox divided most of the farm into blocks of building lots and sold them during the 1860s and 1870s; he also donated land for the Union Theological Seminary along the railroad right-of-way, between 69th and 70th Streets, and just north of it a full square block between Madison and Fourth Avenue, 70th and 71st streets, for the Presbyterian Hospital, which occupied seven somewhat austere structures on the plot; He built the Lenox Library on a full block-front of Fifth Avenue, now the site of the Frick Collection.
Lenox Hill Hospital, the former German Hospital, is located in this area, on East 77th Street.
Luxury residences built in the 1910s and '20s are now very expensive. Park Avenue and Lexington Avenue both pass through Lenox Hill, and along these avenues, there are many boutiques, art galleries and five-star hotels. Museums in the area include the Frick Collection.
As of 2009, the population of the area was 67,122. The population density was approximately 35,960 people per square kilometer. Over 75% of residents were white. The median income for a household living in Lenox Hill was $92,219.
Lenox Hill is serviced by the New York City Subway's 68th Street–Hunter College station on the 4, 6, and <6> trains, as well as the 72nd Street station on the M, N, Q, and R trains. Bus routes include M1, M2, M3, M4, M15, M66, M72, M98, M101, M102, M103.