Development as a residential suburb began in 1967 and was marketed by Stewart Upton a large real estate firm following the subdivision of the area bounded by Duneba and Eucalyptus Drive, and the former riding school which was situated near Billarga Road.

Prior to this time the area was rural with many citrus orchards, with a small number of homes on acreage along Quarter Sessions Rd, extending north towards the former sandstone quarry near "Blackfellow's Head", which was used as a dumping ground for stolen cars of the 1940s and 1950s.

A small parcel of land was opened at the same time on the eastern side of Quarter Sessions Rd and this include Gum Blossom Drive and Bottle Brush Road.

The original alignment still exists as Warrigal Drive, although in very poor condition, passing by the entrance to the former rubbish tip, and providing a second access to the Bushfire Brigade.

The loop constructed at the northern end of Quarter Sessions Road has completely eradicated all traces of the former sandstone quarry which lay to the western side.

On 28 June 2018 it was announced that Westleigh Waterboard would be transformed into a multi-use recreational parkland with $40 Million funding from the Hornsby Shire.

[5] Westleigh Village Shopping Centre, includes two Supermarkets, Aldi and Mint-Fresh IGA, along with a Butcher, Chemist, Baker and other specialist stores.

Most of the suburb (except the southern side) is surrounded by natural bushland, which at times poses significant bush fire danger.

This area is now often used by a wide manner of 'Westleighians' for activities including walking, motorbike riding and general tom-foolerly which has been happening for over 30 years.

Of these:[1] The house in the iconic Australian political comedy drama film Don's Party was located in Westleigh.

Residents include actor Mel Gibson (former resident), David Speers[citation needed] from ABC News, formerly Sky News, Karl Bonnington, Graeme Dunn, Jason Morrison from 2UE,[7] Anthony Leard (District Surveyor from Sydney Lands Dept) and Trevor Long (EFTM and Channel 9 Tech Guru)