The businesswoman from Hull - who won the 2006 series of Lord Sugar's BBC One show and now presents a weekly programme on Sky Sunrise - announced the news on Twitter.
She urged her followers to get themselves checked after what she thought was just a "persistent pimple" turned out to cancerous.
She wrote on Twitter: "Biopsy results received. Turns out that what I thought was a persistent pimple on my face is actually skin cancer."
She also thanked her fans for support and reassured them she's going to be "just fine".
And then added that her tweet had prompted a man to get his own lump checked.