Who voiced Megatron in the original Transformers cartoon?

Frank Welker voiced Megatron in the original Transformers cartoon.

Welker supplied the voice of the Generation 1 Megatron in The Transformers, the American animated series that began in 1984. His performance helped establish Megatron’s distinctive harsh, commanding sound as the leader of the Decepticons. Welker also voiced several other characters in the series, including Soundwave, Skywarp, Rumble, Frenzy, Ravage, Ratbat, Mirage, Trailbreaker, and Sludge.

A common mix-up comes from later adaptations. Hugo Weaving voiced Megatron in the first three live-action Transformers films, while David Kaye voiced the separate Beast Wars version of Megatron. Peter Cullen is best known as the voice of Optimus Prime. Welker also returned to Megatron in later Transformers projects, including Transformers: Prime, and voiced the character in The Last Knight, but those later credits do not change the original cartoon answer.