The Hyperloop is a hypothetical mode of high-speed transportation proposed by the entrepreneur and SpaceX founder Elon Musk.

Musk envisioned the system as a 'fifth mode' of transportation, an alternative to boats, planes, automobiles, and trains. The system would, according to Musk, enable travel from Los Angeles to San Francisco in under 30 minutes, or 343 miles (552 km) at an average speed of more than 685 mph (1,102 km/h).

On August 12, 2013, Musk published a fifty-seven page long Alpha proposal.