Heat the olive oil in a large pot over medium heat. Add the chopped onion and bell pepper and sauté for 5-8 minutes, or until the veggies have softened.
Add the whole chicken breasts to the pot. Pour in the chicken broth, diced tomatoes, taco seasoning, and salt. Bring the mixture to a boil, then reduce the heat to medium-low. Cover the pot and simmer the soup for 15-20 minutes, or until the chicken is fully cooked and tender.
Remove the cooked chicken breasts and shred them using two forks. Return the shredded chicken to the pot.
Stir in the black beans and corn. Simmer the soup for another 5-10 minutes to heat everything through.
Add the softened cream cheese and stir until it fully melts, creating a creamy texture.
Taste and adjust the seasoning as needed. Serve the soup hot with your favorite toppings, like shredded cheese, sour cream, cilantro, diced avocado, lime wedges, and/or tortilla chips.