Add flour, seasoned salt, corn meal, black pepper, paprika, and cayenne pepper to a paper bag or ziptop bag and shake to mix well.
Dip each onion ring into seasoned flour then dip into buttermilk then back into seasoned flour coating all sides. Set each battered onion ring on a parchment covered baking sheet to rest until all onion rings are battered (about 10-15 minutes after dredging).
While coating sets, add 3-3 ½ inches of oil to a cast iron or heavy bottom pot and heat over medium high heat. Heat oil to 365 to 375 F degrees.
Fry the rings 4-5 at a time depending on the width of your pot making sure not to overcrowd. Fry on each side until golden brown then remove and place on paper towels to drain or add to a wire rack to drain over a paper towel lined baking sheet.