Preheat an outdoor grill for medium heat and lightly oil the grate. Place a grill basket on the grill, so excess oil falls through.

Pour frozen Brussels sprouts into a mixing bowl and coat with olive oil. Sprinkle with garlic salt and black pepper. Mix thoroughly. Transfer to the grilling basket.

Cook on the preheated grill until golden and tender, about 15 minutes, turning frequently.

Meanwhile, place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes.

Transfer grilled Brussels sprouts back to the mixing bowl and top with bacon.