To reheat chicken in the oven, preheat your oven to 425 to 475 °F (218 to 246 °C). Different ovens vary in the amount of time they take to preheat. Bearing this in mind, then, you will need to make sure that the oven is up to the right temperature before you put the chicken in for reheating.
Once you have preheated the oven and it’s come up to temperature, place the chicken in the oven. If the chicken has been cut into smaller pieces, it may take only a few minutes to reheat properly so you’ll want to be mindful and watch it to prevent it from drying out. If you are reheating large pieces, such as whole breasts, it is likely that you will have to wait longer.
You will need to reheat the chicken to 165 °F (74 °C). Always use a meat thermometer to check the internal temperature and to make sure that the chicken has been reheated thoroughly all the way through.