The Eastern Distributor is a 4.7-kilometre-long (2.9 mi) motorway in Sydney, New South Wales, Australia. Part of the M1 and the Sydney Orbital Network, the motorway links the Sydney central business district with the south-east and Sydney Airport. The Eastern Distributor separates Sydney's Eastern Suburbs from Sydney's Inner-Southern Suburbs. The centre-piece is a 1.7 km (1.1 mi) tunnel running from Woolloomooloo to Surry Hills. Built as a build-own-operate-transfer project, it is 75% owned by Transurban.

The motorway opened to traffic in December 1999, with the project fully completed in July 2000. It is only tolled in the northbound direction.

Transurban considers the southern end of Cahill Expressway (including the Domain Tunnel) to be part of the Eastern Distributor, and denotes the latter to have a total length of 6 kilometres (4 mi). The length of 4.7 kilometres (2.9 mi) used in this article refers to the length of the motorway constructed in the 1990s between the southern end of Cahill Expressway (Cowper Wharf Road) and the northern end of Southern Cross Drive (Link Road).

The Eastern Distributor commences at the southern end of Cahill Expressway and the interchange with Cowper Wharf Road in Woolloomooloo and heads in a southerly direction as a dual-carriageway six-lane surface road, before entering piggyback tunnels shortly afterwards under the suburbs of Woolloomooloo and Darlinghurst, with a subterranean interchange with the Cross City Tunnel for direct connections to the Western Distributor. After returning to the surface in Moore Park, it continues south in a trench inside South Dowling Street, before ending at the interchange with Link Road and continuing south as Southern Cross Drive.

The project's centrepiece is the 1.7-kilometre (1.1 mi) piggyback tunnel under one of Australia's most densely populated urban areas, necessitated due to the requirement of three lanes in each direction within the existing roadway corridor. The unique double-deck, three lanes per direction design comprises a large, single tunnel excavation. At mid-height through the excavation, a precast concrete ledge forms the base of the northbound tunnel, with the southbound tunnel slotting below. As a result, only one tunnel roof was created with the lower southbound carriageway built in a slot. According to the Australasian Tunnelling Society, no records are available of any piggyback tunnel (rail or road) where the upper carriageway has been carried on prestressed concrete planks resting on sidewall ledges. In the main tunnel there is a central length of 0.5 kilometres (0.3 mi) where the span is typically greater than 17 metres (56 ft), and of note, there is no record of any road tunnel with spans greater than this where permanent roof support comprises rockbolts and shotcrete only and with vertical unsupported sidewalls of rock.

At the time it was built, the tunnel's claim to fame was that at 24.5 metres (80 ft) across at its widest point, it was the widest tunnel in the world. This point occurs where the William Street on ramp tunnel merges with the main tunnel. At 14 metres (46 ft), the tunnel is also notably tall (from the ceiling to the floor).

The tunnels of the Eastern Distributor are fully equipped with lighting, ventilation, drainage, CCTV surveillance, fire fighting and emergency control systems.

The need for an Eastern Distributor was first discussed in the early 1950s in the County of Cumberland planning scheme.