To answer the question directly, no, Simon Cowell does not own 'America's Got Talent' (AGT). The show is produced by Fremantle, a global television production and distribution company, and Syco Entertainment, which is Cowell's own production company. While Cowell plays a significant role in the show's creative direction and is a prominent judge, the ownership is shared among various entities.
What is Syco Entertainment?
Syco Entertainment, founded by Simon Cowell, is a British television and music production company. It is known for producing several successful talent shows, including 'The X Factor' and 'Britain's Got Talent.' Syco holds a stake in AGT, thus allowing Cowell to have considerable influence over the show's format and direction, but it does not equate to outright ownership.