Hendrik Simons, known as Heintje and later on as Hein Simons, (born August 12, 1955, Bleijerheide, a section of Kerkrade, Netherlands), is a Dutch singer and actor.

Heintje was the son of a coal miner who had to retire because of silicosis, reducing the family to near poverty. The family opened a smal shop and Heintje used to sing along with the jukebox. When he was 11, he entered a singing contest in the next town. He beat out 30 competitors to win the contest. His manager Addy Kleyngel, heard about him and went to audition him at his home. After hearing only a few notes, he took him on as a client. On becoming wealthy, Heintje moved his family back to his father's birthplace Neu Moresnet, Belgium, where he still lives to this day.

He became particularly famous as a child singer, with his hit song "Mama" in 1967, and as a child actor, with his appearances in numerous German films in the 1960s and 1970s (some of these were dubbed into English and also Afrikaans). He also enjoyed success with English songs, notably of which is "I'm Your Little Boy". In 1971, The Los Angeles Times described him as, "the hottest property in Europe." The same article quoted the Frankfurter Allgemeine Zeitung as saying of him, "No one is bigger in German show business."