Horst Blankenburg (born 10 July 1947) is a former German footballer, who played as a sweeper.
He is best known for the early 1970s period, during which he played for Ajax Amsterdam and won the European Cup three times (1971, 1972, 1973), the European Super Cup twice (1972, 1973), the Intercontinental Cup once (1972) and the Dutch championship and the KNVB Cup twice.
In 1976, he won the German Cup and the European Cup Winners' Cup in 1977 with Hamburger SV.
He was never selected for the German national team.