Idiom or proverb that implies " the evidence contradicts what you claim"

"The evidence suggests otherwise."

This is similar to medica's answer, but it seems to be quite common, at least where I live (the Southeastern U.S.) Google's n-gram viewer seems to suggest this one is more common.

The facts speak for themselves.

It's commonly used to tell people that there's no point in denying an allegation because evidence proving the allegation is overwhelming.

macmillandictionary.com definition:

used for saying that the facts of a particular situation provide all the necessary, true information about it

"You can't deny you took the rooster, the facts speak for themselves."

In scientific circles, the expression "Nevertheless it moves" has some resonance as a way of implying "the evidence contradicts what you claim." The quotation is attributed to Galileo, speaking (or muttering to himself) after being forced to recant his support for Copernicus's heliocentric description of the solar system. The story is retold (with considerable skepticism as to the incident's ever actually having happened) in Wyndham Lewis and the Cultures of Modernity (2013):

Galileo was condemned in 1633 by the Catholic Church, and ordered not to repeat his belief that the earth moved [around the sun]. The story is told that 'the moment he was set at liberty, he looked up to the sky and down to the ground and, stamping with his foot, in a contemplative mood, said Eppur si muove; that is, still it moves, meaning the earth'. This was first published by Giuseppe Baretti in London in 1757.

The idea here is something like "You can make me say it isn't so, but that doesn't mean it isn't so." It is thus something you might say not to an accused person who boldly denies something that the evidence clearly points to, but (at a safe distance) to someone who has just forced you to affirm something that you know isn't true. In any event, many English-speaking scientists (and others) will recognize the allusion when someone responds to an emotionally or politically powerful but unscientific attack by saying, "Nevertheless it moves."

Similar: "Don't piss on my head and tell me it's raining."