The superstar rapper was spotted catching the Jubilee Line tube at Waterloo station on Saturday evening (12 October) ahead of his sold-out 'Magna Carta Holy Grail' show and he even took along his good friends Chris Martin and producer Timbaland.
A few starstruck Londoners caught Jay (real name Shawn Carter) and his crew using the public transport and managed to take some unbelievable snapshots of the world-famous artists travelling to the arena.
One fan captured Jay stood in a carriage with Coldplay's Chris, while they both appeared to be laughing. Perhaps they found the sheer craziness of catching the tube amusing?
The fan captioned his picture: "What a riot... Just met Jay Z on the tube in London."
Just look at that huge gold chain!
Another photo shows 43-year-old Jay leaning against the wall at Waterloo station with members of his entourage, as Timbaland busied himself by playing some music in his headphones.
If only Beyoncé had joined them, now that would've been amazing!
Jay-Z isn't the first celeb to surprise Underground passengers by catching the tube, since Rihanna also decided to try out public transport on the way to her gig back in 2011.
And apparently ex-couple Kristen Stewart and Robert Pattinson were spotted on the tube during their time in the UK last Christmas.
Although we can imagine that for first-timers on the London Underground, like Jay-Z, it all might be quite a novel experience, we'd love to know what they think of the tube during rush hour!
Have you ever seen a celeb on the tube? Let us know below, as the best comment each week wins £50!