The former Busted star has been handed a short contract by bosses of the Bbc show and will play the love interest of popular character Stacey Branning, portrayed by Lacey Turner.
Willis says, "I am so thrilled to be a part of such an iconic show. I grew up watching EastEnders, so this is really exciting for me."
His stint in the serial drama will start in 2014, which looks set to be a busy year for the star - he is going on tour with newly formed supergroup MCBusted, an amalgamation of Busted and MCFly members.
The 30 year old will also star in the reboot of British sitcom Birds of a Feather.