Cooking chicken breast in the Oven at 375F should take from 45 to 60 minutes.
Before placing the chicken breast in the oven preheat the oven to your 375 F temperature and then place the chicken breast in the oven and set a timer for 45 minutes.
Once 45 minutes have passed then open the oven door and check the chicken with a knife to see if there's any red spots or blood in the chicken and if there is then put it back in the oven and reset the timer for another 15 minutes and then check the chicken again.
The chicken should be fully cooked within 60 minutes when baking it at 375 F.
You can cook the chicken in less time by turning the oven up to 400 F and the chicken should fully be cooked in 45 minutes instead of an hour.