The Homestead Extension of Florida's Turnpike (HEFT), designated as unsigned State Road 821 (SR 821), is the southern extension of Florida's Turnpike, a toll road in the U.S. state of Florida maintained by Florida's Turnpike Enterprise (FTE). Spanning approximately 48 miles (77 km) along a north–south axis, it supplements the 265-mile (426 km) mainline (designated as SR 91) to form the complete 309-mile (497 km) turnpike. The extension begins at its southern terminus at U.S. Route 1 (US 1) in Florida City, and transitions into the SR 91 mainline in Miramar at its northern end. Despite their designations as different state roads, the mainline and the extension are continuous in their exit numbering.

It was opened in stages between 1973 and 1974, after the mainline of the Turnpike was completed, and is used by both commuters and travelers to the Florida Keys and Everglades National Park. Due to its alignment, it acts as a de facto outer beltway for Miami, with the Palmetto Expressway (State Road 826) forming an inner beltway.