Seinfeld font here refers to the font used in the logo of Seinfeld, which is an American television sitcom that was first broadcast on NBC in 1989.
The Seinfeld logo features the Seinfeld logotype in red over a tilted yellow oval. The logotype lettering is very similar to a font called ITC Fenice Std Oblique, with modification on the letter “i”. The font is a commercial one and you can purchase it here.
The Fenice font identified above is not available for free, please follow the link above and purchase the font. Meanwhile, you can take a look at our collection of fonts for cars, pop music and apparel, some of which are available for free download.