Abstract This article addresses the claims that the idea of a flat earth was an essential part of the dominant cosmological paradigm in the Middle Ages. After examining the origin and transmission of the main arguments that ancient science passed on to medieval scholars with respect to the signs and evidence of the earths (almost) spherical shape, we will also explore both ancient and medieval advocates of alternative models, only to conclude that throughout the Middle Ages the standard scientific paradigm involved the notion of a spherical earth. The (inaccurate) belief that medieval science generally upheld the flat earth paradigm seems to be part of a widespread prejudice held in contemporary times against the Middle Ages writ large. En el cine, en series y otros programas de televisión, en novelas, historietas, videojuegos y otros medios de la cultura de masas, la misma idea se ha reflejado una y otra vez, con distintos grados de distorsión, más o menos completa y sugerida o expresada con mayor o menor claridad.