Flinders Island is an island in the Bass Strait, located 20 km from Cape Portland being the north-eastern tip of Tasmania, Australia. It is the largest island in the Furneaux Group.
The island is approximately 62 km from north to south, and 37 km from east to west. The island's total land area is 1333 km². With a height of 756 m, Mount Strzelecki in the south west is the island's highest peak. About a third of the island is mountainous and rugged with ridges of granite running the length of the island. The coastal areas are dominated by sandy deposits often taking the shape of dunes. Many coastal lagoons punctuate the eastern shore, formed by dunes blocking further drainage. This drainage is mainly provided by many small streams, few of them permanently flowing, directly leading to the waters of Bass Strait or such a lagoon.
The coastal areas are mainly covered in scrub or shrubs, whereas the vegetation at a higher elevation consists of woodland, mainly eucalyptus species. The total number of plant species in the Furneaux Group well exceeds 800, showing the great biodiversity of its ecosystem. Animal species include Bennett's Wallaby (Macropus rufogriseus), Brushtail Possum (Trichosurus vulpecula), Cape Barren Goose (Cereopsis novaehollandiae), Short-tailed Shearwater (Puffinus tenuirostris), Eastern Pygmy Possum (Cercartetus nanus), Potoroo (Potorous apicalis), Common Ringtail Possum (Pseudocheirus peregrinus), Tasmanian Pademelon (Thylogale billardierii), and Cape Fur Seal (Arctocephalus pusillus). The area surrounding Mount Strzelecki in the south west of the island constitutes Strzelecki National Park.
Settlements include Whitemark (which has the island's main airstrip and about 170 inhabitants (2005) and Lady Barron (approx. 130 inhabitants), Blue Rocks, Emita, Killiecrankie, Lackrana, Leeka, Loccota, Lughrata, Memana, Palana, Ranga, Wingaroo, and Wybalenna (all below Lady Barron's population figure).
| Average Annual Temperature: | 10 to 18 °C (50 to 64 °F) |
| Average January Temperature: | 13 to 22 °C (60 to 71 °F) |
| Average July Temperature: | 6 to 13 °C (43 to 56 °F) |
| Days over 30 °C (86 °F): | 4.8 |
| Days over 35 °C (95 °F): | 0.8 |
| Days under 2 °C (35.6 °F): | 21.1 |
| Days under 0 °C (32 °F): | 5.6 |
| Annual Rainfall: | 754 mm (29.7 inches) |
| Average Annual Windspeed: | 21–25 km/h (13–15 mi/h) |