| Flinders Highway | |
| Formerly | |
| Length | 410 km (255 mi) |
| Direction | Northwest-Southeast |
| From | Eyre Highway, Ceduna |
| via | Smoky Bay, Streaky Bay, Port Kenny, Elliston |
| To | Lincoln Highway, Port Lincoln |
| Major junctions | Tod Highway |
Flinders Highway connects the South Australian towns of Ceduna and Port Lincoln, a distance of 410 kilometres. The highway was formerly designated as National Route Alternate 1 and currently signed as B100. The National Route Alternate 1 presents an alternative but somewhat longer coastal route between Port Augusta and Ceduna, compared to the more direct Eyre Highway.
It runs parallel to the western coasts of the Eyre Peninsula. It is named after the explorer Matthew Flinders who sighted these coasts in the early 19th century. Only small settlements lie along its track. Of these, Coffin Bay is a centre for oyster farming, Elliston is renowned for surfing and fishing and Ceduna itself is a base for whale watching.