An ancient Egyptian calendar of lucky and unlucky days composed some 3,200 years ago is said to be the oldest historical documentation of the discovery of Algol.

[19] The variability of Algol was noted in 1667 by Italian astronomer Geminiano Montanari,[20] but the periodic nature of its variations in brightness was not recognized until more than a century later, when the British amateur astronomer John Goodricke also proposed a mechanism for the star's variability.

[23] In 1881, the Harvard astronomer Edward Charles Pickering presented evidence that Algol was actually an eclipsing binary.

[24] This was confirmed a few years later, in 1889, when the Potsdam astronomer Hermann Carl Vogel found periodic doppler shifts in the spectrum of Algol, inferring variations in the radial velocity of this binary system.

Joel Stebbins at the University of Illinois Observatory used an early selenium cell photometer to produce the first-ever photoelectric study of a variable star.

The x-ray flares are thought to be caused by the magnetic fields of the A and B components interacting with the mass transfer.

[36][37] The secondary component was identified as the radio emitting source in Algol using Very-long-baseline interferometry by Lestrade and co-authors.

[38] Mass transfer between the components is small in the Algol system[39] but could be a significant source of period change in other Algol-type binaries.

[7] About 7.3 million years ago it passed within 9.8 light-years of the Solar System[40] and its apparent magnitude was about −2.5, which is considerably brighter than the star Sirius is today.

Consequently, the Chinese name for β Persei itself is 大陵五 (Dà Líng wu, English: The Fifth Star of Mausoleum.).

[49] The Algol system usually has an apparent magnitude of 2.1, similar to those of Mirfak (α Persei) at 1.9 and Almach (γ Andromedae) at 2.2, with whom it forms a right triangle.

Historically, the star has received a strong association with bloody violence across a wide variety of cultures.

In the Tetrabiblos, the 2nd-century astrological text of the Alexandrian astronomer Ptolemy, Algol is referred to as "the Gorgon of Perseus" and associated with death by decapitation: a theme which mirrors the myth of the hero Perseus's victory over the snake-haired Gorgon Medusa.