The Lord of the Rings: The Return of the King is a 2003 epic fantasy-drama film directed by Peter Jackson. It is the concluding film in The Lord of the Rings film trilogy, following The Fellowship of the Ring (2001) and The Two Towers (2002).

The Lord of the Rings: The Return of the King brings Peter Jackson's mammoth adaptation of J.R.R. Tolkien's classic to a close in suitably epic fashion. Instead of starting just where the previous film left off, however, it goes far back in time to the moment the tormented creature Gollum first came to possess the One Ring. In this flashback, actor Andy Serkis (who voiced Gollum and performed his movements onset prior to the final CGI effects) finally gets to appear onscreen, portraying Gollum's former self, Sméagol. This disturbing scene serves as a potent reminder that the Ring seeks to corrupt even the well-intentioned Frodo (Elijah Wood), who is increasingly struggling with the dark power of the Ring himself. Thus, the film returns to the present, following Frodo, Sam (Sean Astin), and Gollum as they journey ever closer to the foreboding land of Mordor. They pass by the terrifying dark city of Minas Morgul, watching as the dreadful army of the Witch King sets out for the human strongholds in Gondor, and move on to the rocky stairs to Cirith Ungol, where an even darker enemy lies in wait. Meanwhile, the rest of the Fellowship reunites in Rohan, having defeated the wizard Saruman on two different fronts, at Helm's Deep and Isengard. They are not together for long, though, since the hobbit Pippin (Billy Boyd) gets into trouble, making it necessary for him and Gandalf (Ian McKellen) to hastily depart for Minas Tirith, capital of Gondor. Once there, they find the steward of Gondor, Denethor (John Noble), in an unstable mental state and the city preparing for battle against the amassing forces of Sauron. Denethor unwisely sends his only remaining son, Faramir (David Wenham), back into bloody battle to prove himself. He returns nearly dead, sending Denethor over the edge of sanity.In another realm, elf Arwen (Liv Tyler) begins her journey to immortal life in the Grey Havens, on her way to leave Middle-earth -- and Aragorn (Viggo Mortensen) -- forever, but has a vision that causes her to once again reconsider her decision. Back in Rohan, the men are preparing to ride to Gondor's aide. éowyn (Miranda Otto) desperately wants to join the men in battle, but her uncle, King Théoden (Bernard Hill), orders her to stay and defend Rohan if necessary. The hobbit Merry (Dominic Monaghan) also desires to ride with the men, but is denied due to his small size and inexperience. Aragorn is met there by the elf Elrond (Hugo Weaving), who brings him the re-forged Sword that was Broken (in the ancient battle with Sauron) and urges him to take a different route to Gondor. Heeding Elrond's advice, Aragorn, along with elf Legolas (Orlando Bloom) and dwarf Gimli (John Rhys-Davies), takes a cavernous path through the mountains, where they meet ghoulish ghosts who betrayed Aragorn's ancestors and are doomed to eternal unrest unless they fulfill their broken oaths by aiding him. All but Frodo, Sam, and Gollum will meet on the massive battlefield of the Pelennor before the gates of Minas Tirith. The former three instead engage in a battle of wills between each other and the One Ring as they head toward the fires of Mount Doom to destroy it.

Released on 17 December 2003, The Lord of the Rings: The Return of the King received rave reviews and became one of the greatest critical and box-office successes of all time, being only the second film to gross $1 billion worldwide, becoming the highest grossing film from New Line Cinema, as well as the biggest financial success for Time Warner in general, until Harry Potter and the Deathly Hallows – Part 2 surpassed The Return of the King's final gross in 2011.

Notably, it won all eleven Academy Awards for which it was nominated, an Oscar record, and tied for largest number of awards won with Ben-Hur and Titanic. It also won the Academy Award for Best Picture, the first and only time a fantasy film has done so; it was also the second sequel to win a Best Picture Oscar (following The Godfather Part II) and the only time a sequel has won without a predecessor winning the award. It was the highest-grossing film of 2003.