Kenneth Arnold makes the first widely reported UFO sighting near Mount Rainier, Washington.

The Kenneth Arnold UFO sighting occurred on June 24, 1947, when private pilot Kenneth Arnold claimed that he saw a string of nine, shiny unidentified flying objects flying past Mount Rainier at speeds that Arnold estimated at a minimum of 1,200 miles an hour (1,932 km/hr). This was the first post-World War II sighting in the United States that garnered nationwide news coverage and is credited with being the first of the modern era of UFO sightings, including numerous reported sightings over the next two to three weeks. Arnold's description of the objects also led to the press quickly coining the terms flying saucer and flying disc as popular descriptive terms for UFOs.

Kenneth Albert Arnold (March 29, 1915 – January 16, 1984) was an American aviator, businessman, and politician.

He is best known for making what is generally considered the first widely reported modern unidentified flying object sighting in the United States, after claiming to have seen nine unusual objects flying in tandem near Mount Rainier, Washington on June 24, 1947. After his alleged sighting, Arnold investigated reports of UFOs, writing and speaking about the topic for years to come.

In 1962, Arnold won his party's nomination for Lieutenant Governor, losing in the general election.