The Christian libertarian and former Presidential nominee was caught by savvy internet users after allegedly liking the clip.
The shocking footage, sourced from a well known explicit website, features a woman performing an act of self-love whilst watching a couple performing sexual acts.
The video has caused shock online, with many mocking Donald Trump’s former rival.
One wrote: “Damn Ted Cruz is this really what goes on down on capitol hill?”
Another added: “Ted, what are you up to this evening?”
A third wrote: “My young daughters and sons follow you for good wholesome content can you please explain this?”.
It is currently unclear if Ted Cruz himself liked the post, or if someone else was using his account at the time.
While running for President Mr Cruz hit out at now-leader of the free world Donald Trump as “utterly amoral” and a “serial philanderer”.
At the time then-Candidate Trump tweeted: “How can Ted Cruz be an Evangelical Christian when he lies so much and is so dishonest?”
The two have since made their peace after a furious presidential primary that saw Trump shock the world and make his way to the White House.
Express.co.uk has attempted to reach Mr Cruz for comment.