Somerton Tunnel is a railway tunnel in Somerset which is located between Somerton and Langport. It is situated on the Reading to Taunton Line. It was built by the GWR, and work finished in 1906, as part of the constructing of the Langport and Castle Cary Railway. The structure is just under a kilometre long.
One workman was killed during the building of the tunnel when some blasting dynamite, which was being used to excavate the area, failed to detonate as planned.
Not far from the west end of the tunnel, in Long Sutton, there is an old derelict building which is said to have been used as an explosives store for the GWR engineers at the time of construction. Some of the other explosives were stored in a Powder House in neighbouring village Charlton Mackrell, and the structure does also still stand today.