Horsburgh Lighthouse is an active lighthouse which marks the eastern entrance to the Straits of Singapore. It is situated on the island of Pedra Branca. Singapore's earliest lighthouse by date of completion, it is located approximately 54 kilometres (34 mi) to the east of Singapore and 14 kilometres (8.7 mi) from the Malaysian state of Johor.

Pedra Branca is an outlying island and the easternmost point of Singapore. The name of the island, which is Portuguese for "white rock", refers to whitish guano deposited on the rock. The island consists of a small outcrop of granite rocks with an area of about 8,560 square metres (92,100 sq ft) at low tide. During the low water spring tide it measures, at its longest, 137 metres (449 ft) and has an average width of 60 metres (200 ft). Pedra Branca is situated at 1°19′48″N 104°24′27″E, where the Singapore Strait meets the South China Sea.