Prepare the ingredients. Gather everything you need. Drain the canned chicken, soften the cream cheese, and shred the Cheddar cheese if necessary.
Heat the chicken and hot sauce. Place a large skillet over medium heat. Add the drained chicken and hot pepper sauce. Cook for 3–5 minutes, stirring occasionally, until the chicken is heated through and coated in the sauce.
Add the cream cheese and ranch. Stir the softened cream cheese and ranch dressing into the chicken mixture. Continue cooking for 3–5 minutes, stirring frequently, until the cream cheese melts and the mixture becomes smooth, creamy, and warm.
Mix in half the cheddar. Add half of the shredded Cheddar cheese (¾ cup) to the skillet. Stir until evenly combined with the creamy chicken mixture.
Transfer to the slow cooker. Spoon the prepared mixture into a slow cooker, spreading it into an even layer.
Add the remaining cheese. Sprinkle the remaining ¾ cup shredded Cheddar cheese evenly over the top.
Cook until hot and bubbly. Cover the slow cooker and cook on Low for approximately 35 minutes, or until the dip is thoroughly heated, bubbling, and the cheese on top has melted.
Serve warm. Serve the Buffalo chicken dip directly from the slow cooker with celery sticks and chicken-flavored crackers, if desired.