James Edward Keeler (September 10 1857 – August 12 1900) was an American astronomer.

He worked at Lick Observatory beginning in 1888 but was appointed director of Allegheny Observatory in 1891. He returned to Lick Observatory as its director in 1898, but died not long after in 1900.

He did a spectroscopic study of Saturn's rings and proved that they could not be solid objects because they did not rotate at a uniform rate; rather, they had to consist of a swarm of small individual objects.

He won the Henry Draper Medal in 1899.

He discovered two asteroids, although the second was lost and only recovered about 100 years later.

In 1880, Allegheny Observatory director Samuel Pierpont Langley, accompanied by Keeler and others, went on a scientific expedition to the summit of Mount Whitney. The purpose of the expedition was to study how the Sun's radiation was selectively absorbed by the Earth's atmosphere, comparing the results at high altitude with those found at lower levels.

As a result of the expedition, the "Keeler Needle " (14,240 ft.) near Mount Whitney was named after James E. Keeler, and the "Day Needle " (14,180 ft.) was named after another expedition participant, Professor William Cathcart Day of Johns Hopkins University. The Day Needle has now been renamed Crooks Peak after Hilda Crooks .