The television series Lost had six seasons. ABC broadcast the series from 2004 through 2010, ending its run after 121 episodes.
The six-season structure covers the survivors’ changing understanding of the island, including its communities, scientific mysteries, and supernatural elements. The story moves between different time periods and increasingly focuses on the island’s long history.
The final three seasons were produced under a planned end-date arrangement announced by ABC, allowing the creators to conclude the narrative rather than continue indefinitely. This helped shape the show’s later pacing and its emphasis on resolving major mysteries.
Lost is sometimes remembered as having more seasons because of its many flashbacks, flash-forwards, and time shifts. Those are storytelling devices within the six-season run, not separate seasons. The series finale, “The End,” aired in May 2010.