St James' Hospital was a mental health facility at Milton, Portsmouth, Hampshire, England.

[1] The hospital, which was designed by George Rake in the Gothic Revival style using a dual pavilion layout, opened as the Portsmouth Borough Asylum in September 1879.

[2] It became the Borough of Portsmouth Mental Hospital in 1914 and was requisitioned for military use during the First World War.

[3] After the introduction of Care in the Community in the early 1980s, the hospital went into a period of decline and inpatient services significantly reduced.

[4] By summer 2018, Solent NHS Trust only retained a small area of the site for mental health services.