The Cranborne Chase Area of Outstanding Natural Beauty is following Exmoor and been designated an international dark sky reserve.
It is the first AONB in the country to be designated in its entirety and the 14th reserve across the world.
The AONB runs across Wiltshire, Dorset, Hampshire and Somerset and the status shows controls are in place to prevent light pollution.
Linda Nunn, director of Cranborne Chase AONB, said: "We think of our beautiful landscapes as being on the ground, but 50% of our landscape is above our heads, in the sky,
"Here in Cranborne Chase we can see the Milky Way and the Andromeda Galaxy, if the clouds allow.
"The AONB has pledged to protect and improve its dark sky for future generations.
"There are huge benefits for nocturnal wildlife, our own human health and wellbeing, for education, tourism and for energy saving. We're thrilled to be playing our part."
Bob Mizon, who leads the Commission for Dark Skies in the UK and has played a major supporting role in the application, added: "You can’t fail to be amazed by the show the night sky puts on when you’re in Cranborne Chase AONB on a clear night. This dark sky status helps to keep it that way for future generations."
Linda Nunn, continued: "We have taken meter readings of the darkness of the night sky for several years and we are hugely grateful to the Wessex Astronomical Society for their support.
"We must also thank Bob Mizon as we could not have achieved this without his help, or the support of the local authorities and parish councils and we look forward to working with them as we continue to improve our dark skies.
"Although huge amounts of work have already been done to achieve this status, we must continually improve our dark skies.
"Dark sky friendly schemes with schools, business, parishes and landowners are being developed and Wiltshire Council, which administers two-thirds of the area, has already agreed to upgrade its street lighting.
"This will make a significant contribution and will help us continually improve our dark sky quality.
"This is a requirement of the International Dark-Sky Association to ensure we maintain our exclusive status."