St Augustine’s Hospital (1875–1993) was a psychiatric hospital in Chartham, Kent. It was founded as the second, or East, Kent County Asylum in 1872. In 1948 the hospital became part of the National Health Service and was renamed St Augustine's Hospital. The hospital gained notoriety in the 1970s when it was the subject of a committee of inquiry into malpractice and mismanagement. St Augustine's Hospital closed in 1993 and the site is now occupied by housing, although a few of the original hospital buildings remain.

When it became clear in the early 1870s that the Kent County Asylum at Barming Heath, Maidstone, was no longer large enough to accommodate all the county's pauper lunatics, a search began for a site for a second county asylum as the 1845 Lunacy Act had made it obligatory to provide asylums. A 120-acre (49 ha) site on Chartham Downs three miles south-west of Canterbury was chosen. It satisfied the requirements set down by the Commissioners in Lunacy: a site on elevated ground with cheerful prospects and enough space to provide employment and recreation for inmates while preventing them being overlooked or disturbed by strangers. It was also conveniently close to a railway station and situated centrally in its catchment area and not too far from the nearest large town.

The competition for the design of the buildings was won by the London firm of architects J. Giles and Gough. John Giles was one of the most successful asylum architects, winning eight of the sixteen competitions he entered and coming second in four. The buildings were completed in 1876 at a total cost of £211,852. Originally built to house 870 patients, the hospital gradually expanded and by 1948 had 300 acres, including a farm, and 73 staff residences, as well as new blocks and facilities for patients. Eventually there would be 2,000 patients.

Although the initial building programme was not completed until 1876, the first patients, all of them pauper lunatics from the Kent County Asylum at Barming Heath, had been able to move in the previous year. The first medical superintendent was Robert Spencer. The asylum was originally managed by a committee of quarter sessions, with responsibility passing to in 1889. In 1920 Kent County Mental Hospitals Committee took over the management and the asylum was renamed Kent County Mental Hospital, Chartham.The hospital became a self-contained village, with its own farm, workshops, baker, butcher, fire-brigade, church, graveyard, gasworks, cricket team, band, etc. Male patients worked on the farm, while female patients worked in the laundry or as seamstresses.

During the first world war, the asylum took in patients from other parts of the country, when their hospitals were being used for military casualties. After the end of the war they had a number of service patients (there were 37 in 1922), ex-servicemen who had special privileges. During the second world war, part of the hospital was taken over by the Emergency Medical Service for military use.