Place the shredded chicken in a large mixing bowl.
Add the Greek yogurt to the chicken, stirring with a fork until the chicken is well coated with a creamy mixture.
Sprinkle the garlic powder and celery seed evenly over the mixture, then fold them in gently to distribute the flavors.
Chop the celery finely and stir it into the salad for a crisp texture and fresh flavor.
If desired, fold in a tablespoon of mayonnaise for extra creaminess and richness.
Season with salt and pepper to taste, then gently fold everything together until evenly combined.
Cover the bowl and refrigerate for at least 30 minutes to let the flavors meld and the mixture chill.
Serve the salad chilled or at room temperature, with or without additional garnishes like fresh herbs or sliced bread.