Peel each onion and cut into thirds, separating the onion slices into rings. Using two slices of bacon, wrap around the onion ring until the ring is fully covered, securing in place with a toothpick. Continue until all the bacon is used up.
Place the onion rings on the and grill until the bacon is cooked, about 20 minutes.
Serve on top of burgers, or on their own with your favorite dip!