Start by placing the boneless skinless chicken breasts at the bottom of your crockpot. You can season them lightly with salt and pepper if desired.
Open the can of crushed pineapple and pour it over the chicken. Make sure to include the juice, as it will contribute to the flavor and moisture.
Next, take your bottle of sweet BBQ sauce and pour it over the pineapple and chicken. Ensure that the chicken is well-coated with the sauce for maximum flavor.
Cover your crockpot with its lid and set it to cook on low for 6-8 hours or on high for 3-4 hours. The longer you cook it, the more tender the chicken will become.
Once the cooking time is up, shred the chicken directly in the crockpot using two forks. Stir everything together to combine the shredded chicken with the sauce and pineapple. Serve hot over rice, in a sandwich, or however you prefer.