Lake Victoria is one of the African Great Lakes. With a surface area of approximately 59,947 km² (23,146 sq mi), Lake Victoria is Africa's largest lake by area, the world's largest tropical lake, and the world's second-largest fresh water lake by surface area after Lake Superior in North America. In terms of volume, Lake Victoria is the world's ninth-largest continental lake, containing about 2,424 km³ (1.965×10⁹ acre⋅ft) of water. Lake Victoria occupies a shallow depression in Africa. The lake has an average depth of 40 m (130 ft) and a maximum depth of 80–84 m (262–276 ft). Its catchment area covers 169,858 km² (65,583 sq mi). The lake has a shoreline of 7,142 km (4,438 mi) when digitized at the 1:25,000 level, with islands constituting 3.7% of this length.

The lake's area is divided among three countries: Kenya occupies 6% (4,100 km² (1,600 sq mi)), Uganda 45% (31,000 km² (12,000 sq mi)), and Tanzania 49% (33,700 km² (13,000 sq mi)).

Though having multiple local language names (Dholuo: Nam Lolwe; Luganda: 'Nnalubaale; Kinyarwanda: Nyanza; also Ukerewe), the lake was renamed after Queen Victoria by the explorer John Hanning Speke, the first Briton to document it in 1858, while on an expedition with Richard Francis Burton. The lake is home to many species of fish which live nowhere else, especially cichlids. Invasive fish, such as the Nile perch, have driven many endemic species to extinction.