The region, in north-west England, joins sites including the Taj Mahal, the Grand Canyon and Stonehenge on the prestigious list.
See also: Northern Lights over the Lake District
The culture organisation tweeted: "Just inscribed as @UNESCO #WorldHeritage Site: The English Lake District."
Lord Clark of Windermere, who chaired the Lake District's bid, said the decision to recognise the region's culture, art and literature, as well as its landscape, was "momentous".
He said: "It is this exceptional blend which makes our Lake District so spectacularly unique and we are delighted Unesco has agreed.
"A great many people have come together to make this happen and we believe the decision will have long and lasting benefits for the spectacular Lake District landscape, the 18 million visitors we welcome every year and for the people who call the National Park their home."
Today's announcement in Krakow has led to jubilation among 25 organisations in the Lake District National Park Partnership who had put the bid together for UNESCO recognition in the cultural landscape category.
Lake District National Park Chief Executive, Richard Leafe, said there was great excitement over the achievement.
He said: "The Lake District is an evolving landscape that has changed over time and will continue to do so. Improving landscape biodiversity and looking after our cultural heritage underpin the Partnership's management plan which sets out how, together, we will look after the National Park as a World Heritage Site for everyone to enjoy."
The bid was submitted by the Department for Digital, Culture, Media and Sport and Historic England as the UK's only submission in 2016.
The Lake District World Heritage Site is...
1. One of just over 1,000 World Heritage sites (1052)
2. The UK's largest World Heritage site: 229,200 ha (1951 boundary)
3. The UK's 31st UNESCO World Heritage site
4. The only UK National Park that will be entirely a World Heritage site
5. The UK's 5th cultural landscape World Heritage Site, joining:
· Blaenavon Industrial Landscape
· Cornwall and West Devon Mining Landscape
· Royal Botanic Gardens, Kew
· St Kilda
6. Cumbria's second World Heritage Site together with Hadrian's Wall
7. One of eight World Heritage Sites looked after by the National Trust
8. One of 15 National Parks. The others are: Brecon Beacons, the Cairngorms, Dartmoor, Exmoor, Loch Lomond and Trossachs, Northumberland, North York Moors, Peak District, Pembrokeshire Coast, Snowdonia, the Yorkshire Dales, the Broads, the New Forest and the South Downs.