Born in Toronto Canada, and immigrated to Israel from with his family at age 11.
During the rest of his childhood, Sagall grew up in Haifa and eventually graduated from the Hebrew Reali School in the city.
His mother, Ruth Sagall, is an actress at the Haifa Theatre.
At a young age, Sagall did stagework for local Israeli theaters. His first appearance as an actor occurred in an 1977 Israeli television film which did not gain much attention. Sagall gained much success after he played Momo in the successful 1978 Israeli film Lemon Popsicle (Eskimo Limon) which later on became an Israeli cult film and was followed by a series of sequels.
In 1979, Sagall was an actor in the New Media Bible Series as Joseph.
In 1983 Sagall played the lead role in the drama Drifting by his boy-friend Amos Gutman, where he played a lonely young homosexual man whom attempts to find love and break into the movie business. During the mid-1980s Sagall began producing and directing short films.
In 1992 Sagall was cast in the role of Poldek Pfefferberg, in the film Schindler's List which was produced and directed by Steven Spielberg.
As a screenwriter and film director Sagall created and directed the 1998 drama film Link City, in which he also played a supporting role. Among the other films he created - The Jewish State and blood.
His 1999 film Urban Feel was entered into the 49th Berlin International Film Festival.
In 2007 Sagall participated in the TV series HaMakom (The Place) in Channel 10.
His 2011 film Lipstikka premiered at the 61st Berlin International Film Festival and was nominated for the Golden Bear.