Last night, Mark and 10 other hopefuls entered the BB house and, tonight, they will be joined by six more.
But while some may have felt nervous in front of the cameras, Mark definitely took it all in his stride!
In 2009, when he was 18, Mark appeared in Channel 4 reality show Shipwrecked: Battle Of The Islands. At the time, Mark worked in Subway and admitted that his biggest challenge would be being away from home.
Then, two years later, Mark turned up on The X Factor, auditioning in front of Gary Barlow, Tulisa Contostavlos, Kelly Rowland and Louis Walsh. However, his rendition of Rihanna's 'Only Girl In The World' didn't go down well.
Gary told him: "Oh Mark, the singing was truly horrible. You didn't sing once in tune."
Perhaps he will have better luck on Big Brother?
Last night, as he headed into the house, Mark spoke of his love for HD brows and admitted that he never thinks before he speaks. He then won £5,000 after being nominated for a reward by fellow housemate Pauline Bennett.
Watch Mark's Shipwrecked profile video and his X Factor audition below!
Check out the first batch of BB housemates here:
Copyright: Channel 5