The Nathaniel Witherell is a rehabilitation and skilled nursing facility at 70 Parsonage Road in Greenwich, Connecticut.

It is owned and operated by the town on a non-profit basis, providing a range of primarily short-term care services on a 24-acre (9.7 ha) campus north of the central business district.

The present main building was constructed in 1932 as an enlargement and functional replacement of the previous facility.

The facilities underwent enlargement in 1961 and 1975, although the Colonial Revival design of the main building, by architect William Tubby, is still discernible.

[3] The facility campus is located about 2 miles (3.2 km) north of downtown Greenwich, occupying 24 acres (9.7 ha) on the west side of Parsonage Road.