Stow Maries Halt is a 2.2-hectare (5.4-acre) nature reserve south of Stow Maries in Essex. It is owned and managed by the Essex Wildlife Trust.

The former Stow St Mary Halt railway station has marshes, a pond and scrub, together with adjoining pasture which is also part of the reserve. Butterflies include purple and white-letter hairstreaks, and there are flowers such as common fleabane and wild carrot.

There is access from Church Lane.

51°39′40″N 0°39′07″E / 51.661°N 0.652°E / 51.661; 0.652