The first season of the television series Lost commenced airing in the United States and Canada on September 22, 2004, concluded on May 25, 2005, and contained 25 episodes.

It introduces the 48 survivors of a plane that broke apart in mid-air, scattering them on a remote island in the South Pacific.

The regular directors throughout the season were J. J. Abrams, Jack Bender, Stephen Williams, Tucker Gates, Greg Yaitanes and Kevin Hooks.

The website's critical consensus reads, "Unpredictable and addictive, Lost is a new kind of TV mystery that grips as often as it guffaws.

"[7] The pilot episode garnered 18.6 million viewers, winning the 9:00 pm (Eastern) timeslot, and giving ABC its strongest ratings since 2000 when Who Wants to Be a Millionaire initially aired—beaten only the following month by the premiere of Desperate Housewives.

[8] Based on its strong opening, Reuters dubbed it a "hit drama" noting that "the show appeared to have benefited from an all-out marketing blitz that included radio spots, special screenings and ABC's first billboard advertising campaign in five years.

Terry O'Quinn and Naveen Andrews received nominations for Outstanding Supporting Actor in a Drama Series.