Hendrik "Henrik" Sillem (12 August 1866 in Amsterdam – 13 July 1907 in Courmayeur, Italy) was a Dutch jurist, mountaineer and sport shooter.

He graduated as Doctor of Law on 8 May 1891, with a thesis 'Het faillissement des verzekeraars' (Bankruptcy of insurance companies)' published by Roeloffzen en Hubner, Amsterdam in 1891.

[citation needed] Henrik Sillem worked in Amsterdam as a lawyer, legal advisor and public prosecutor.

In March 1906, Henrik Sillem made the first ascent of the West Ridge of Mount Cook in New Zealand with guide Peter Graham.

Sillem only reached the age of 40; in 1907 he fell while descending the Aiguille du Midi and was buried nearby, in Courmayeur.