Bluejohn Canyon, Natural canyon in Wayne County, United States.

Bluejohn Canyon is a slot canyon in eastern Wayne County, Utah, on BLM land just south of the Horseshoe Canyon Unit of Canyonlands National Park. Its main fork runs about 11 miles north-northeast from the Robbers Roost Flats as a tributary of Horseshoe Canyon, and it has several tributary canyons of its own. Traversing its full length requires technical canyoneering skills and equipment.

The canyon is probably named for John Griffith, a 19th-century outlaw nicknamed "Blue John" who reportedly kept stolen horses in the area. He had one blue eye and one brown eye. The main fork runs about 11 miles north-northeast from the Robbers Roost Flats as a tributary of Horseshoe Canyon.

The canyon's name comes from John Griffith, a 19th-century outlaw nicknamed "Blue John" for his one blue and one brown eye, who reportedly kept stolen horses in the area. In 2003 Aron Ralston amputated his own right forearm with a multi-tool after a boulder trapped it; his five-day ordeal is told in his autobiography Between a Rock and a Hard Place and the 2010 film 127 Hours.

Visitors need canyoneering experience and proper equipment before entering, as the route requires rappelling skills and technical know-how. Honest self-assessment of your abilities is important, since underestimating the difficulty can create dangerous situations.

The East Fork stands out for its freezing-cold passages and tight slots, offering a distinctly different experience from the Main Fork. This variety makes it possible to explore different routes on separate visits or combine both paths in a single adventure.