Zorb ball is the recreation or sport of rolling downhill inside an orb, generally made of transparent plastic. Zorb ball is generally performed on a gentle slope, but can also be done on a level surface in pubs and clubs around the UK, permitting more rider control. In the absence of hills some operators have constructed inflatable, wooden or metal ramps. There are two types of orbs, harnessed and non-harnessed. Non-harness orbs carry up to three riders, while the harness orbs are constructed for one to two riders. Double-harness spheres have different slope requirements, and must only be operated in specific locations. The longer runs are approximately half a mile. The first zorb ball site was established in Rotorua, New Zealand, by David and Andrew Akers.

The zorb ball, hard plastic single layer spheres made for small rodent pets, has been manufactured and sold since at least the 1970s. A Russian article on the Zorb mentions a similar device having debuted in 1973. In the early 1980s, the Dangerous Sports Club constructed a giant sphere (reportedly 23 metres or 75 feet across) with a gimbal arrangement supporting two deck chairs inside. This device was eventually cut up for scrap, with some of the plastic remnants used to cover a compost heap.

In 1994, Dwane van der Sluis and Andrew Akers conceived the idea for a type of sphere in Auckland, New Zealand, calling their invention the "Zorb". With two other investors they created the firm ZORB Limited, and set to work commercializing sphereing. Their business model was to develop the activity world-wide via a franchise system. In 2000, van der Sluis exited from the company to return to his career as a software engineer; Akers continued to run the company as CEO until April 2006, when he resigned. Around this time, ZORB's European master franchise operator, Michael Stemp, and Hungarian master franchise operator, Attila Csató, ended their affiliation with ZORB and started a manufacturing and sphereing consultancy firm, Downhill Revolution and created the human cocktail maker called Spinfizz. Andrew Akers and his brother David Akers have since teamed up with Chris Roberts to create the OGO (Outdoor Gravity Orb) and The Fishpipe.

Sphereing is also referred to as Orbing or Zorbing, and Zorbing entered the Concise Oxford English Dictionary in 2001 where it was defined as: "a sport in which a participant is secured inside an inner capsule in a large, transparent ball which is then rolled along the ground or down hills".