Park officials said 43-year-old Hans Uhl was part of a commercial river trip.
The group had just started its multiday trip on the Colorado River on Wednesday when park officials received a call around 2 p.m. about an unconscious kayaker at Badger Rapids.
Authorities said Uhl's kayak capsized and he was unable to right himself.
A safety boat was able to reach the kayak, but authorities said Uhl couldn't be resuscitated.
An investigation is being conducted by the National Park Service and the Coconino County medical examiner.
Uhl's hometown in Germany wasn't immediately available Thursday.
Badger Rapid at Mile 8, which is the first major rapid through Grand Canyon. Large side canyons on either side of the river have pushed large amounts of boulders in the channel. Note the V shaped tongue in the middle at the top of the rapid. This is where boats should enter Badger Rapid and continue in a fairly straight line to the smooth water at the end.