Knocking is a 2006 documentary film directed by Joel Engardio and Tom Shepard that focuses on the civil liberties fought for by Jehovah's Witnesses. It focuses primarily on the stories of three Jehovah's Witnesses, and how their lives demonstrate three fundamental Witness teachings that have affected society in general: Conscientious objection, and rejection of blood transfusions and saluting the flag.

Knocking explored how Jehovah's Witnesses played a major role in First Amendment history, setting Supreme Court precedents that expanded individual liberties for all Americans.

In interviews, director Joel Engardio said Knocking is not about the theology of Jehovah's Witnesses but instead uses the religion as a case study to examine how disparate and disagreeable groups can hold their unique beliefs without marginalizing or limiting the freedom of others. "We may not be each others' cup of tea," Engardio said on NPR, "but tolerance allows a variety of kettles to peacefully share the stove."

Knocking won several film festival awards including Best Documentary at the USA Film Festival and was covered in Newsweek, USA Today and newspapers across the United States. Entertainment Weekly named it "What to Watch." Knocking was broadcast in the United States on PBS. It was also broadcast in Australia, Canada, Greece and Israel. Knocking was released on DVD in English, Spanish, Portuguese, Russian and Korean.