NORTHWOOD is a hamlet of Ruislip and an ecclesiastical parish, formed June 16, 1854, from the civil parishes of Ruislip in Middlesex and Rickmansworth and Watford in Herts: it is to the north of Ruislip Wood, on the borders of Hertfordshire, on the road from Harrow to Rickmansworth, with a station on the Metropolitan railway, 3 miles west from Pinner station on the main line of the London and North Western railway, 5 south-west from Watford and 6 north-east from Uxbridge. The parish is in the Uxbridge division of the county, Uxbridge petty sessional division, union and county court district, and in the rural deanery of Uxbridge, archdeaconry of Middlesex and diocese of London. Holy Trinity church, consecrated in 1854, is a building of flint and stone, in the Early English style, consisting of chancel, nave, south porch and a tower on the north side with spire and containing a clock with two dials and one bell, dated 1854: in the chancel is a reredos of alabaster, and there are eight stained windows: the church affords 360 sittings. The register dates from the year 1854. The living is a vicarage, net yearly value £205, with residence, in the gift of trustees, and held since 1895 by the Rev. Edward Batt Backhouse. Lord Ebury and Daniel Norton esq. are the principal landowners. The soil on the low grounds of the parish is clay, with a subsoil of clay; the land is in pasture. On the elevated grounds there are gravel, sand and chalk, with extensive woodlands. The area is 2,338 acres; the rateable value is included in Ruislip; the population in 1891 was 711, of which 173 are in Herts.

National School (mixed), built in 1860, & enlarged in 1892, for 181 children; average attendance, 150.