The Happiest Homecoming on Earth or the Happiest Celebration on Earth was the eighteen-month-long celebration of the 50th anniversary of the Disneyland theme park, which opened on July 17, 1955. It commemorated fifty years of Disney theme parks and celebrated Disneyland's milestone throughout Disney parks all over the globe. The "Homecoming" name was only used for Disneyland Resort; all the other Disney Parks resorts used the "Celebration" name.

Disneyland is a theme park at the Disneyland Resort in Anaheim, California. It was the first theme park opened by the Walt Disney Company and the only one designed and constructed under the direct supervision of Walt Disney, and opened on July 17, 1955.