Johannes Cornelis "Hans" van Houwelingen (born 25 March 1945, Rotterdam) is a Dutch mathematician and a professor emeritus of medical statistics at Leiden University.

[1][2] After graduating from Utrecht University in 1968 with a major in mathematics and a minor in theoretical physics and mathematical statistics, Van Houwelingen started working at Utrecht University at the Institute for Mathematical Statistics.

Van Houwelingen earned his PhD at Utrecht University in 1973; his dissertation, entitled On empirical Bayes rules for the continuous one-parameter exponential family, was supervised by Gerard Jan Leppink.

[1] In his retirement speech on 26 November 2008, Van Houwelingen stated that "Expecting the Unexpected is a very accurate job description for a biostatistician.

The mission of statisticians is to anticipate what could happen and assist others in forming sensible responses.