Blue Mountains

Blue Mountains may mean:

Geography
Blue Mountains (New South Wales), Australia
City of Blue Mountains, a local government area west of Sydney
Blue Mountains railway line
Electoral district of Blue Mountains
Greater Blue Mountains Area, a World Heritage Site
Blue Mountains (Nunavut), Canada
The Blue Mountains, Ontario, a town in Canada
Blue Mountains (Congo), northwest of Lake Albert
Sinimäed Hills (Blue Mountains) in Estonia, near Narva
Nilgiri mountains (Blue Mountains), southern India
Blue Mountains (Jamaica) 
Blue Mountains (New Zealand), in West Otago
Blue Mountains (Niger), a mountain range near the Aïr Mountains in Niger
Blue Mountains (Oregon), United States
Blue Mountains (ecoregion), a Level III ecoregion
Blue Mountains or Abajo Mountains, Utah, United States
Blue Mountains Line, a railway line in New South Wales
Fictional
The Blue Mountains (Elgar), a song about Australia by Sir Edward Elgar to a poem by Alfred Noyes
The Blue Mountains (fairy tale), a fairy tale by Andrew Lang in The Yellow Fairy Book
Blue Mountains (Middle-earth) or Ered Luin, fictional mountains in Tolkien's Middle-earth