The Spandau Ballet and EastEnders star, the bookmakers' favourite to win the series, made his entrance on Wednesday, August 15.
Sadie Frost, whose first husband was Martin's brother Gary Kemp, wrote on Twitter: "Lovely to see @realmartinkemp on BB - he should win."
Boy George simply tweeted: "Martin to win!"
Fellow soap actor Cheryl Fergison has also become popular among viewers and bookmakers since she entered the house.
Celebrity Big Brother continues tonight (Friday, August 17) at 9pm on Channel 5.
Photo gallery - Celebrity Big Brother day 3:
Copyright: Channel 5