I have a red growth on the inside of my cheek where my teeth meets my cheek it hurts what could this be?

Cheek bite?: it could be as simple as a cheek bite or something more. To be sure you should always have it evaluated.

Growth: it is impossible to tell you exactly what this is without seeing it so get to a dentist ASAP. This my be a wisdom tooth causing this, cheek bite, infection or something else.

Could be: Could be result of trauma(bite), burn, viral/fungal/bacterial infection, , drainage from infected tooth, one of many benign or neoplasticism tumors, or a host of other problems. See your Dentist or an Oral Surgeon ASAP for diagnosis and, if required, appropriate Rx, especially if lesion is growing.

Morsicatio Buccarum: also called chronic cheek biting. rinse with warm salt water 3-4 times a day, Ibuprofen or Tylenol (acetaminophen) (one tab.3-4 hours as needed for pain) work well to alleviate the tenderness and discomfort. Also apply compounded topical cream. If concerned, see your dentist for evaluation.

It's a red growth: If has been there for more than two weeks, it should be examined by a local dentist or oral surgeon. Without knowing anything about your bite, the condition of your teeth, or social habits like smoking or tobacco chewing, it is impossible to tell what it is over the the internet.