The X Factor 2012 runner-up will release his debut album in May, and will start recording his first collection after finishing the upcoming X Factor live tour.
"I'm so excited about signing to RCA. They have such a rich heritage of amazing artists," Douglas said in a statement.
"Colin Barlow (head of RCA) and his team share my vision of being a timeless artist and I can't wait to start recording my first album… let the journey begin."
Douglas first confirmed a deal with Sony Music back in December, along with fellow X Factor finalists Union J and Ella Henderson.
X Factor champion James Arthur signed a deal with Syco as part of his prize for winning the talent competition.
Watch Jahmene Douglas perform 'Angels' at the X Factor live final 2012 below: