The starry nights and lack of light pollution on Coll in the Inner Hebrides won it the title of dark sky community.
The island was given the special conservation status by the International Dark-Sky Association, and islanders hope it will attract more stargazers.
Galloway Forest, Scotland's other dark sky site, has benefited from a tourist boom since it was awarded the status in November 2009.
Tony Oliver, a member of Coll Dark Skies Group, said: "The first winter on Coll I was in awe of the night sky, it's on a par with many of the high Arctic regions I'd visited.
"Soon I discovered Coll had some real star gazers which eventually led, over many pints, to where we are today. The island community is very nature aware and needed little encouragement to offer support.
"Now we have the opportunity to share our darkness with others and I hope anyone visiting Coll off-season will be equally inspired."
The award follows years of work by the group to preserve the view of the night sky.
They used a sky quality meter, a handheld device which records brightness, to measure the darkness of the night sky over the island.
An urban sky would normally read around 17 on the scale, while a site completely free from light pollution would read 22.
Readings of 21.9 were regularly recorded on Coll, making its skies some of the darkest in Europe.
International Dark-Sky Association member Steve Owens said: "This is a fantastic achievement for Coll, placing them in a very select family of places around the world that have worked to protect their night sky.
"The fact that the UK now has one quarter of all of the International Dark Sky Places across the globe shows that there is a real appetite here for night sky protection, and for establishing places where anyone can enjoy the wonder of the night sky."
Coll's application was supported by Argyll and Bute Council.
Councillor Fred Hall said: "The Isle of Coll is a unique island in many ways, not least of which is its beautiful countryside and sea views but also the lack of light pollution. I can think of no better island in the inner Hebrides to gain the dark skies accolade."
The island was awarded dark sky status at the same time as Northumberland dark sky park in England, bringing the total number of conservation areas in the UK to six.