National Cheese Toast Day is observed worldwide every September 15, celebrating the simple yet delicious dish known as cheese toast, or cheese on toast. This holiday honors a popular food item that consists of a slice of toasted bread topped with melted cheese, often made with cheddar, Emmental, or Gruyere, among others. The dish has historical roots, with similar recipes like Welsh rarebit dating back to the early 18th century. In the United States, Del Johnson, founder of Sizzler Family Steak House, is credited with popularizing cheese toast in the late 1950s. Sizzler created National Cheese Toast Day in 2015, offering free samples and events to celebrate this signature dish. People commemorate the day by enjoying cheese toast at restaurants, cooking it at home, and sharing their creations on social media with specific hashtags.