Comedian Jerry Seinfeld will be the first guest on Jay Leno's new primetime TV show in September, NBC said. The star and co-creator of the 1990s TV comedy “Seinfeld” will help kick off “The Jay Leno Show” when it premieres on NBC on September 14. Seinfeld, one of America's most popular comedians, will join R&B singers Kanye West, Rihanna and Jay-Z, who will be performing on the opening show.