Insidious is a 2010 supernatural horror film directed by James Wan, written by Leigh Whannell, and starring Patrick Wilson, Rose Byrne, and Barbara Hershey.

It is the first installment in the Insidious franchise, and the third in terms of the series' in-story chronology.

The story centers on a married couple whose boy inexplicably enters a comatose state and becomes a vessel for a variety of demonic entities in an astral plane.