In a large bowl, combine celery, grapes, onion, cranberries, and chicken breast.
In a small bowl, whisk together sugar, lemon juice, and salt. Pour over the chicken salad mixture and mix until everything is evenly coated.
Gently fold in the Greek yogurt until it’s fully incorporated into the salad.
Sprinkle in the roughly chopped pecans, stirring to combine all of the ingredients. Taste and adjust seasonings if desired.
Serve chilled with your favorite bread or crackers, or enjoy it as a standalone dish! If desired, garnish with extra cranberries and/or pecans.