The first land grant in this area was for a farm in 1794, to former convict and jailor Henry Kable.
The land in the eastern corner of Summer Hill was an additional grant of 30 acres (12 ha) made to Henry Kable in 1804.
This eastern corner would subsequently become part of the estate of James Underwood.
Underwood died in 1844 and left a will so complicated that it required special legislation before it could be subdivided.

The earliest known use of the name "Summer Hill" was in 1876, for a land subdivision adjacent to the present-day St Andrew's Anglican Church.
The name Summer Hill is thought to be a name chosen by the land sub-divider, presumably based on an attachment for England.
Local historians regard the suggestion that the name is a derivation of "Sunning Hill" as a dubious story which has no substance.

Summer Hill's largest mansion, Carleton (now the Grosvenor Hospital's main building), was built in the early 1880s on Liverpool Road for Charles Carleton Skarrat.
The suburb boomed with the opening of the railway station in 1879, and was followed by subdivision of much of the surrounding area.
Between 1880 and 1910, the area became an upper-class suburb, and was a popular choice for professionals in banking and insurance who worked in the city.
Subdivision of gardens for housing continued in the 1920s and 1930s, and socioeconomically the suburb changed as some of the wealthier inhabitants moved to the North Shore.
Demolition of most of the surviving mansions in the 1970s allowed erection of home units, especially within walking distance of the railway station.
The first land grant in this area was for a farm in 1794, to former convict and jailor Henry Kable. The land in the eastern corner of Summer Hill was an additional grant of 30 acres (12 ha) made to Henry Kable in 1804. This eastern corner would subsequently become part of the estate of James Underwood. Underwood died in 1844 and left a will so complicated that it required special legislation before it could be subdivided.
The earliest known use of the name "Summer Hill" was in 1876, for a land subdivision adjacent to the present-day St Andrew's Anglican Church. The name Summer Hill is thought to be a name chosen by the land sub-divider, presumably based on an attachment for England. Local historians regard the suggestion that the name is a derivation of "Sunning Hill" as a dubious story which has no substance.
Summer Hill's largest mansion, Carleton (now the Grosvenor Hospital's main building), was built in the early 1880s on Liverpool Road for Charles Carleton Skarrat. The suburb boomed with the opening of the railway station in 1879, and was followed by subdivision of much of the surrounding area. Between 1880 and 1910, the area became an upper-class suburb, and was a popular choice for professionals in banking and insurance who worked in the city. Subdivision of gardens for housing continued in the 1920s and 1930s, and socioeconomically the suburb changed as some of the wealthier inhabitants moved to the North Shore. Demolition of most of the surviving mansions in the 1970s allowed erection of home units, especially within walking distance of the railway station.
Summer Hill, New South Wales