Gray played the alcoholic wife of scheming oil baron J.R. Ewing in the hit soap, and her onscreen husband Larry Hagman revealed earlier this year (11) he downed booze onset to relieve the boredom of shooting scenes.
His revelation sparked speculation the actors were all boozing during filming - but Gray insists such behaviour would have clashed with the heavy workload.
She tells Britain's OK! magazine, "That is absolutely not correct. If you drink when you are acting - on a series, where we did 28 shows a year - nothing would get done.
"I'm not an alcoholic. People say, 'Oh, you did a great job of playing an alcoholic. She did it so good, then she must be an alcoholic.' Please, just congratulate me on my acting!"