Developers Coronation Power and Airtricity Holdings (UK) Ltd appealed to the Planning Inspectorate after two local authorities had opposed two wind power schemes at Bickham Moor, near Oakford, and Three Moors, near Knowstone.
The proposals were opposed by the Rural Exmoor Alliance, formed by the Two Moors Campaign, the Exmoor Society and the Campaign to Protect Rural England (CPRE) to fight the schemes.
Rachel Thomas, of the Exmoor Society, said: "This is fantastic news for Exmoor National Park. Both these appeals would have had a detrimental impact on the special qualities of the National Park and it's setting."
Caroline Harvey, secretary of the Two Moors Campaign, was jubilant with the decision, which was announced last Friday.
"The campaign and our supporters have worked tirelessly to prevent our wonderful countryside being ruined by these ineffective industrial monsters.
"People should remember that during the recent cold and snowy weather no electricity would have been generated from these white elephants," she said.
The larger of the schemes was the one at Three Moors, proposing nine turbines in total and located within the boundaries of North Devon Council, while the Bickham Moor scheme with four blades fell within the jurisdiction of Mid Devon District Council. A joint inquiry was held involving both applications.
Inspector Philip Major said the proposed development would be "seriously harmful to the character and appearance of the area and the setting of Exmoor National Park".
He also considered that it would go against national development plan policies, and that, on balance, the harm would outweigh the benefits.