Ap Lei Pai, Tidal island in Southern District, Hong Kong.

Ap Lei Pai is an uninhabited islet south of Ap Lei Chau, linked to the base of Mount Johnston by a tombolo that can be crossed at low tide. Apart from a small pier and a lighthouse near its southern tip, Ap Lei Pai Tsui, the island has almost no buildings.

The island has remained largely untouched throughout Hong Kong's urban transformation, preserving part of the region's original geography. A lighthouse was built here to aid shipping traffic in these waters.

The island's only structures are a small pier and a lighthouse near Ap Lei Jue at its southern tip. The name Ap Lei Pai means "duck tongue island," echoing Ap Lei Chau, whose shape resembles a duck's tongue. Since the MTR South Island Line opened, Mount Johnston has become a hiking spot, and unlicensed boat operators ran kai-to routes to the island until a collision on 27 March 2021 led to marine police patrols.

Getting to the island requires careful planning around tide schedules, since the sandbar is only accessible when the tide is low. Bring proper hiking gear for the journey, as there are no facilities or emergency services along the route.

The tombolo links Ap Lei Pai to the base of Mount Johnston on Ap Lei Chau, and the crossing is only passable at low tide. The route from Lei Tung station over Mount Johnston to the lighthouse pier at Ap Lei Pai's southern tip takes about two hours. The island has no residents; apart from a small pier and lighthouse near Ap Lei Pai Tsui, it holds almost no buildings.