If you mean it was raw when originally frozen, then you defrosted & cooked it (like mince for example), then yes, you can. I've just made some meatballs with previously frozen minced beef, cooked them and I'm going to freeze the ones I couldn't eat. I often freeze leftover cooked meat from the Sunday roast, for a curry or stir fry later on.
as long as you cook the food and it's not a "ready meal" and you are thinking of freezing left overs. A very good way to get food poisoning. If you take out meat that was frozen raw for example and made a pie,stew or roast it and want to freeze it down for later or leftovers then make sure it is cooled as quickly as possible and frozen as soon as it is cool, or if you can't put it in the fridge and freeze it within 8 hours.