Lady Robinsons Beach is the stretch of beach between the mouth of the Cooks River and the mouth of Georges River on the western shore of Botany Bay in Sydney, New South Wales, Australia. Originally known as Seven Mile Beach, it was renamed after the wife of the then Governor, Sir Hercules Robinson. Isolated settlements separated from the beach by sand dunes were also given the name of Lady Robinson's Beach as their postal address.

Being Sydney's longest beach, Lady Robinsons Beach is the eastern boundary of the area known as the St George District. It is also the eastern boundary of the Municipality of Rockdale and of the suburbs of Kyeemagh, Brighton-Le-Sands, Monterey, Ramsgate Beach, Sans Souci, Dolls Point and Sandringham.

Lady Robinsons Beach was formed by the erosion of the Hawkesbury sandstone which is still evident as rocky outcrops and cliffs located 1-3 kilometres west of the beach. The sand of the beach and its dunes is a pale yellow, almost white at parts (such as in Dolls Point), and is fine-grained. Nonetheless, it is the whitest beach in the Sydney area.

The beach is limited to the north and to the south by the Wianamatta shale through which the Cooks River and Georges River and their tributaries have carved their lower reaches and mouths. Marshes form and mangroves grow in the eroded shale. These marshes and mangroves restricted access from the north to what became the St George district south of Cooks River. In the early years of settlement these marshes caused numerous other problems for the nearby suburbs. These two types of rock form an integral part of the geological entity, the Sydney Basin SydneyBasin.

Lady Robinsons Beach has a number of prominent beaches on its stretch (from north to south):

The underwater sand flats adjacent to the beach were the habitat of a number of mollusc species, including sand-snails (Uber species), wedge-pipis (Amesodesma species) and Bankivia. Their shells littered the beach. After their habitat was destroyed by a storm in 1966 these species disappeared. The shells found on the beach after this disaster were those of molluscs inhabiting the mudflats of the Georges River and southern part of Botany Bay. These include the Sydney cockle (Anadara trapezia), the large Sydney whelk also known as the Hercules club shell (Pyrazus australis) and a similar, smaller whelk, (Velacumantis ebininus).

Before the third runway of Sydney Airport was extended in the late 1950s, nereid worms were abundant on sand flats at the northern end of the beach. These sand flats were covered with very shallow water which warmed in the sun during daylight hours, encouraging the colourful worms to emerge from their burrows.

Although they didn't land there, this beach is one of the first landmarks that Captain James Cook and his crew in 1770, and later Captain Arthur Phillip and his crew in 1788, would have seen as they sailed through the mouth of Botany Bay. In 1839 a dam with a carriageway was constructed across the Cooks River from what are now Tempe to Arncliffe. This dam remained the major access to the district south of the river for approximately the next fifty years. About five years later Rocky Point Road was built from the tiny settlement south of the dam to Rocky Point on Georges River. This new road meant land access was now closer to Seven Mile Beach.