The Hazards of Helen is an American adventure film serial of 119 twelve-minute episodes released over a span of slightly more than two years by the Kalem Company between November 7, 1914, and February 24, 1917. At 23.8 hours, it is one of the longest non-feature-length motion picture series ever filmed, and is believed to be the longest of the film serial format. Based on a novel by John Russell Corvell and the play by Denman Thompson, the series was adapted to the silent screen by W. Scott Darling.

A serial film, film serial, movie serial, or chapter play, is a motion picture form popular during the first half of the 20th century, consisting of a series of short subjects exhibited in consecutive order at one theater, generally advancing weekly, until the series is completed. Usually, each serial involves a single set of characters, protagonistic and antagonistic, involved in a single story, which has been edited into chapters after the fashion of serial fiction and the episodes cannot be shown out of order or as a single or a random collection of short subjects.