| Birth Date: | 23 January 1927 |
| Birth Place: | Hilversum, the Netherlands |
| Death Date: | 28 January 2002 (aged 75) |
| Death Place: | Alphen aan den Rijn, the Netherlands |
| Sport: | Water polo |
| Club: | HZC de Robben, Hilversum |
Hendrikus "Hennie" Zacharias Keetelaar (23 January 1927 – 28 January 2002) was a Dutch water polo competitor. He played two matches at the 1948 Summer Olympics where his team won a bronze medal. He won a European title two years later.