Remove any wilted, limp outer leaves from the head of lettuce. Cut the lettuce into 4 equal wedges, trimming the base slightly if needed so they sit flat.
Place each wedge on a serving plate or large platter.
Sprinkle each wedge evenly with crumbled bacon, halved cherry tomatoes, red onion, and blue cheese crumbles.
Spoon or drizzle blue cheese dressing over each wedge just before serving.