Preheat the oven to 450 degrees. Mix the chicken with 3/4 cup of barbecue sauce. Brush 1/4 cup of barbecue sauce over the pizza crust.
Scatter the chicken pieces and scallions on top of the crust. Sprinkle the cheese evenly over the other ingredients.
Bake the pizza about 10 minutes, until it is heated through and the cheese is melted.
Cook's Note: You can also use leftover barbecued chicken, or coat boneless, diced chicken breast with barbecue sauce and microwave, covered, until the chicken is cooked through (3 to 4 minutes).