In large saucepot, cover potatoes with water; add salt, if desired. Bring to a boil over high heat. Reduce heat to low and simmer uncovered 10 minutes or until potatoes are tender. Drain potatoes and rinse with cold water until cool.
In large bowl, combine Wish-Bone® Ranch Dressing, celery and onion. Add potatoes; toss gently. Season to taste with salt and ground black pepper. Serve chilled or at room temperature.