John Noble is an Australian actor. He is best known for his roles as Denethor in The Lord of the Rings film trilogy (2001–2003), and Dr. Walter Bishop in the Fox science fiction series Fringe (2008–2013). His other television credits include the supernatural drama Sleepy Hollow (2013–2017) and the police procedural Elementary (2015–2019).

Denethor II, son of Ecthelion II, is a fictional character in J. R. R. Tolkien's novel The Lord of the Rings. He was the 26th ruling Steward of Gondor, committing suicide in the besieged city of Minas Tirith during the Battle of the Pelennor Fields.