The Olympic flame is a symbol used in the Olympic movement. It is also a symbol of continuity between ancient and modern games. The Olympic flame is lit at Olympia, Greece. This ceremony starts the Olympic torch relay, which formally ends with the lighting of the Olympic cauldron during the opening ceremony of the Olympic Games. Through 2022, the flame would continue to burn in the cauldron for the duration of the Games, until it was extinguished during the Olympic closing ceremony. In 2024, electric lighting and mist were used to create a simulated flame for the Olympic cauldron, with the actual flame kept in a lantern exhibited at an adjacent location. That lantern was then taken by French swimmer Léon Marchand from Jardins des Tuileries (where the Olympic cauldron, that was extinguished at that moment, was located) and ceremonially "transferred" to the Stade de France at the start of the Closing Ceremony; there it was finally extinguished just after the IOC president officially closed the Games.

The first time that a symbolic flame made its appearance in the Summer Olympic Games was for the 1928 Summer Olympics in Amsterdam. The main purpose of this fire, placed in a large bowl on top of a slender tower, named "the Marathon Tower", was to indicate for miles around where in Amsterdam the Olympic Games were being held. This tower was associated with the marathon race and all its elements, including the fire, were an idea of the architect Jan Wils who also had designed the stadium.

The idea for the Olympic flame was derived from ancient Greek ceremonies where a sacred fire was kept burning throughout the celebration of the ancient Olympics on the altar of the sanctuary of Hestia. In Ancient Greek mythology, fire had divine connotations and it was thought to have been stolen from the gods by Prometheus. Sacred fires were present at many ancient Greek sanctuaries, including those at Olympia. Every four years, when Zeus was honoured at the Olympic Games, additional fires were lit at his temple and that of his wife, Hera. The modern Olympic flame is ignited every two years in front of the ruins of the temple of Hera.

When the idea of a symbolic fire was introduced during the 1928 Summer Olympics, an employee of the Electric Utility of Amsterdam lit the first symbolic flame in the Marathon Tower of the Olympic Stadium in Amsterdam. The Olympic flame and the Olympic torch relay was first introduced to the Summer Olympics at the 1936 Summer Olympics in Berlin by Carl Diem. The first ever torch-lighting ceremony was held in Olympia, Greece on July 20th, 1936. The torches used were made by Krupp, and the mirror used to light the flame was made by Zeiss Optics, both companies with links to the Nazi government of the time.

The Olympic flame is ignited 100 days before the opening ceremony of the Olympic Games at the main site of the ancient Olympics in Olympia, Greece.

A group of women representing the Vestal Virgins (usually 11 in number) perform a celebration at the Temple of Hera, during which a fire is kindled by the light of the Sun, its rays concentrated by a parabolic mirror. The fire is used to light the first torch of the Olympic Torch Relay. Where cloudy weather prevents the use of the parabolic mirror on the day of the ceremony (as in 2024), a backup flame is used that has been lit during a prior dress rehearsal. An actress plays the role of the temple's high priestess and presents the torch and an olive branch to the first relay bearer, usually a Greek athlete who has already qualified to compete in that edition of the Games. This is followed by a recitation of a poem by Pindar, and the release of a flock of doves to symbolize peace.^{[citation needed]}

At the beginning of the ceremony, the Olympic hymn is sung first followed by the national anthem of the country hosting the Olympics and the national anthem of Greece along with the hoisting of the flags.

After the ceremony at Olympia the Olympic flame first travels Greece. It first goes to the Coubertin Grove on the site of the International Olympic Academy, where it is used to light an altar beside the final resting place of Pierre de Coubertin's heart. The flame is then transferred during a ceremony in the Panathenaic Stadium in Athens from the Hellenic Olympic Committee to the current year's National Olympic Committee (NOC) and local Organizing Committee (OCOG) hosts.