Klaas Willem Ruis (29 March 1945 in Haarlem – 4 August 1986 in Dénia) was a Dutch game show presenter.

He presented the Willem Ruis Show for the KRO and the Willem Ruis Lottoshow, 5 tegen 5 and the Sterrenshow for the VARA.

He died of a cardiac arrest during a vacation in Spain.

Ruis was unhappy with his director at the KRO, who he felt did not allow him to show off all his talents, and got a contract with the VARA, which was losing viewers to the competition and was looking for a star to bolster its roster.

He was paid a salary unheard of at the time (Hfl 300,000 per year, high enough to lead to questions in parliament).