Place orange juice, cranberries, and sugar in a 1 1/2-quart pot over medium heat. Cook until sugar dissolves and cranberries start to pop, about 5 minutes.
Remove from heat and stir in orange gelatin. Let cool to room temperature, at least 20 minutes. Stir in bananas, apple, celery, and walnuts. Refrigerate until set, 4 hours to overnight.
