The original station was opened by the London and South Western Railway on 1 May 1861 and named Portswood after the small village to the west of the main line.
Shortly after, to accommodate the Portsmouth branch line, a new station building was built 0.25 miles (0.40 km) to the south; the relocated station was opened on 5 March 1866.
However to avoid confusion with Portsmouth, the station was renamed to St Denys on 1 January 1876.

The station buildings themselves are fine examples of Victorian architecture.
The original station building on platform 1 is listed, although it is now privately owned.
Platforms 2 and 3 house the waiting room and ticket window, whilst the old station buildings on platform 4 house The Solent Model Railway Group, a local organisation.
The original station was opened by the London and South Western Railway on 1 May 1861 and named Portswood after the small village to the west of the main line. Shortly after, to accommodate the Portsmouth branch line, a new station building was built 0.25 miles (0.40 km) to the south; the relocated station was opened on 5 March 1866. However to avoid confusion with Portsmouth, the station was renamed to St Denys on 1 January 1876.
The station buildings themselves are fine examples of Victorian architecture. The original station building on platform 1 is listed, although it is now privately owned. Platforms 2 and 3 house the waiting room and ticket window, whilst the old station buildings on platform 4 house The Solent Model Railway Group, a local organisation.
St Denys railway station