Wilder has not fought since he was beaten by Tyson Fury for a second time in their trilogy fight last October.
Fury knocked out the American in the 11th round at the T-Mobile Arena in Las Vegas to retain his WBC heavyweight title.
Wilder will end his exile from the ring against Finland's Helenius at Barclays Center in New York.
The 36 year-old, known as the 'Bronze Bomber', said: "It's been a long journey for me and as of today it continues. I thought so many times about whether I should stay out of the business or come back.
"Once I got my statue in my hometown and saw so many people arrive and celebrate with me and my family, to see all the emotions, grown men crying in front of their children and saying he is a real true king, made me feel like my job is not done.
"So, here I am once again, looking forward to returning to the ring. I am looking forward to coming to Barclays Center, a place where I have had my most devastating knockouts and a place I consider my second home.
"So where all my Bombzquad people at? It's time to put on your war gear. And let's go to work, baby. Bombzquad is back!"