The Bagsværd-based firm said that Sørensen, who was declared the world's top-performing CEO in a global ranking from the Harvard Business Review, would abandon his position by the end of 2016.
He will be replaced by Lars Fruergaard Jørgensen, the company's current executive vice president.
Sørensen has been with Novo Nordisk for 35 years and has been at the company's helm for 16.
During that time, the company has grown to become the world's largest maker of insulin, controlling 47 percent of the global market for insulin products.
The company has performed particularly well on the North American market, which accounted for 61 percent of Novo Nordisk's growth in 2014. The company's presence in the US was further boosted after the Food and Drug Administration approved Novo Nordisk's obesity drug Saxenda.
"It has been an honour to work here for more than 30 years and to serve as CEO during a period where we have been able to grow our business, build a strong pipeline and launch important new products to the benefit of our patients, our shareholders and our employees,” Sørensen said in a statement.
Jørgensen said he was "proud and humble” to take over the reins.
"On the one hand, Novo Nordisk has never had a stronger portfolio and organisation; on the other hand, we are facing an unprecedented level of payer pressure and competition. I love challenges, and therefore I can't think of a more exciting time to be offered the job of CEO in Novo Nordisk - a company I have served for more than 25 years and am really passionate about,” he said.