Blue John may refer to:
- Derbyshire Blue John, a form of fluorite mined in Derbyshire, England
- Blue John Cavern, a cavern in Castleton, Derbyshire where fluorite is mined
- Blue John Canyon, a canyon in Utah, United States, site of the Aron Ralston accident
- Blue John (album), an album by organist John Patton
- Lance-Constable Bluejohn, a character in the Discworld series, a member of Ankh-Morpork City Watch
- Blue John Gap, a fictional location in Arthur Conan Doyle's short story "The Terror of Blue John Gap"
Famous quotes containing the words blue and/or john:
“Notice how he has numbered the blue veins
in my breast. Moreover there are ten freckles.
Now he goes left. Now he goes right.
He is building a city, a city of flesh.
He’s an industrialist.”
—Anne Sexton (1928–1974)
“Mothers have as powerful an influence over the welfare of future generations, as all other causes combined.”
—John Abbott. The Mother at Home; or the Principles of Maternal Duty, John Abbott, Crocker and Brewster (1833)