[psim1]

Martin, son of Fly, the first time traveler and inventor of rock-and-roll music.

[soperj]

Technically Einstein was the first time traveler. He traveled one minute into the future.

[fuzz_junket]

Technically Doc Brown was alive in 1885, having travelled there from 1955, so he was the first time traveller by a good 100 years before Einstein.

[myroon5]

Source: https://youtu.be/nNM9nzeifuI