Place whole chicken, chopped onion, and celery in a large pot with 4 quarts of water.
Bring to a boil, then reduce heat and simmer until chicken is cooked through, about 45-60 minutes.
Remove chicken from pot and let cool slightly. Shred the meat and set aside.
Strain the broth if desired for a clearer soup, then return to pot.
Add frozen corn to the broth and simmer for 10 minutes.
Return shredded chicken to the pot and stir to combine.
Season with salt and pepper to taste. Simmer for 5 more minutes and serve hot.