Aliens of the Deep is a 2005 American documentary film directed in part by James Cameron alongside fellow cameraman and friend Steven Quale, who served as second unit director on Cameron's Titanic (1997) and later Avatar (2009), and filmed in the IMAX 3D format.

Cameron teams with NASA scientists to explore the mid-ocean ridges, submerged chains of mountains in the Atlantic and Pacific oceans that are home to some of the planet's more unusual forms of life.

Cameron joins up aboard the Russian research vessel Akademik Mstislav Keldysh with a group of NASA scientists, as well as some American marine biologists, to investigate ten hydrothermal vents in both the Atlantic and Pacific.

The documentary shows Cameron's passion for exploring the oceans, as well as his interest in extraterrestrial life.

The film is similar to Cameron's earlier documentary, Ghosts of the Abyss (2003), which involves him journeying to the wreck of the RMS Titanic.