Cook the bacon in a large skillet over medium heat until crisp, 6 to 8 minutes. Transfer to a paper towel-lined plate.
Make 4 sandwiches with the bacon, Cheddar, tomatoes, and bread. Spread ½ tablespoon of butter on the top and bottom of each sandwich.
Heat a large skillet over medium heat and cook until the sandwiches are golden and the cheese has melted, 2 to 3 minutes per side.