Juhan Ulfsak (born April 18, 1973 in Tallinn) is an Estonian actor.

In 1995, he graduated as an actor from the Viljandi Culture College (where he later worked as a drama teacher), while simultaneously improving his skills at the Helsinki Theater College. Since 1998, an actor at the Von Krahl Theater. Over the years, he has worked with many different directors and theater troupes in Estonia and abroad. Received several awards as an actor (Estonian Theater Awards Best Actor Award 2012 and others).

He is also a recognized film actor, having played in the films of, for example, Veiko Õunpuu, Rainer Sarnet, Pirjo Honkasalo, Christopher Nolan ("Tenet", 2020). As a director, Juhan Ulfsak has done important works at the Von Krahl Theater, the NO99 Theater and the Drama Theater, interpreting the works of Lars von Trier, Sarah Kane, Taavi Eelmaa and Michel Houellebecq.

Juhan Ulfsak's father is actor and director Lembit Ulfsak, and his half-sister is film journalist Maria Ulfsak.