In a saucepan, bring cranberry juice to a boil over medium heat. Remove from the heat; add gelatin, stirring until gelatin is dissolved. Transfer to a small bowl; set aside.
Place cranberry sauce in another small bowl, beat for 1 minute. Stir into gelatin mixture. Refrigerate until partially set. Gently stir in whipped topping. Spoon into dessert dishes. Refrigerate until firm.