Charles Marshall Pratt (March 5, 1939 – December 16, 2000) was an American rock climber known for big wall climbing first ascents in Yosemite Valley.

Pratt wrote in the 1965 American Alpine Journal: "By the fourth day, Yvon had lost so much weight from dehydration that he could lower his climbing knickers without undoing a single button.

For the first time in seven years, I was able to remove a ring from my finger, and Harding, whose resemblance to the classical conception of Satan is legendary, took on an even more gaunt and sinister appearance."

[5] From October 22–31, 1964, with Robbins, Frost and Chouinard, Pratt made the first ascent of the North America Wall on El Capitan, YDS VI, 5.8, A5.

"[7] In 1965 he made the first ascent of Entrance Exam (II 5.9) on Arch Rock in Yosemite Valley with Jim Bridwell, Chris Fredericks and Larry Marshik.

[8] That same year, along with Fredericks, he made the first ascent of Twilight Zone (5.10d), in the Cookie Cliff area, still regarded nearly half a century later as a difficult classic Yosemite Valley route.

"[12] Pratt died of a heart attack in his sleep in Sang Khom, Thailand, where he had spent several winters in the last years of his life.