Form ground beef into 3 evenly-sized patties. Place patties in a non-stick skillet and cook over medium heat to desired doneness, about 4 minutes per side for medium. An instant-read thermometer inserted into the center should read at least 150 degrees F (65 degrees C).
Place bacon in a separate skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes. Remove bacon slices and drain on paper towels, reserving bacon grease in the skillet. Add onion to skillet; cook and stir in bacon grease until translucent and browned, about 10 minutes.
Place 1 ground beef patty, 2 slices bacon, and 1/3 of the onions on each roll; top each with barbeque sauce.
