Henriëtte Adriana (Hetty) Blok (Arnhem, 6 januari 1920 - † 6 november 2012) was a Dutch actrice and cabaratiere and singer. But most of all she's known and famous for the role she played as Zuster Klivia in the tv-hitseries from the 60's: Ja Zuster, Nee Zuster (created by Annie M.G. Schmidt)

Also she acted in movies (a.o.Kermis in de regen from 1962 and Brandende Liefde from 1983), she played in the theatre, directed other artists and is a voice-over for many programms on tv or radio.