Crossness is a location in the London Borough of Bexley, close to the southern bank of the River Thames, to the east of Thamesmead, west of Belvedere and north-west of Erith.

The place takes its name from Cross Ness, a specific promontory on the southern bank of the River Thames.

The light is at an elevation of 41 feet (12.5 m) and gives a white 5-second flash visible for 8 miles (12.9 km).

The Ridgeway path, owned by Thames Water and built on top of the southern outfall sewer, stretches 3.5 miles (5.6 km) between Plumstead railway station and the Crossness sewage treatment works.

The nearest station to Crossness is Abbey Wood, almost 2 miles (3.2 km) away.